How can I get the Windows last reboot reason

This article explains in detail how to find the reason for last startup/shutdown. In my case, this was due to windows SCCM pushing updates even though I had it disabled locally. Visit the article for full details with pictures. For reference, here are the steps copy/pasted from the website:

Press the Windows + R keys to open the Run dialog, type eventvwr.msc, and press Enter.

If prompted by UAC, then click/tap on Yes (Windows 7/8) or Continue (Vista).

In the left pane of Event Viewer, double click/tap on Windows Logs to expand it, click on System to select it, then right click on System, and click/tap on Filter Current Log.

Do either step 5 or 6 below for what shutdown events you would like to see.

To See the Dates and Times of All User Shut Downs of the Computer

A) In Event sources, click/tap on the drop down arrow and check the USER32 box.

B) In the All Event IDs field, type 1074, then click/tap on OK.

C) This will give you a list of power off (shutdown) and restart Shutdown Type of events at the top of the middle pane in Event Viewer.

D) You can scroll through these listed events to find the events with power off as the Shutdown Type. You will notice the date and time, and what user was responsible for shutting down the computer per power off event listed.

E) Go to step 7.

To See the Dates and Times of All Unexpected Shut Downs of the Computer

A) In the All Event IDs field, type 6008, then click/tap on OK.

B) This will give you a list of unexpected shutdown events at the top of the middle pane in Event Viewer. You can scroll through these listed events to see the date and time of each one.

Is there a command to restart computer into safe mode?

My first answer!

This will set the safemode switch:

bcdedit /set {current} safeboot minimal

with networking:

bcdedit /set {current} safeboot network

then reboot the machine with

shutdown /r

to put back in normal mode via dos:

bcdedit /deletevalue {current} safeboot

How is the java memory pool divided?

Heap memory

The heap memory is the runtime data area from which the Java VM allocates memory for all class instances and arrays. The heap may be of a fixed or variable size. The garbage collector is an automatic memory management system that reclaims heap memory for objects.

Eden Space: The pool from which memory is initially allocated for most objects.
Survivor Space: The pool containing objects that have survived the garbage collection of the Eden space.
Tenured Generation or Old Gen: The pool containing objects that have existed for some time in the survivor space.

Non-heap memory

Non-heap memory includes a method area shared among all threads and memory required for the internal processing or optimization for the Java VM. It stores per-class structures such as a runtime constant pool, field and method data, and the code for methods and constructors. The method area is logically part of the heap but, depending on the implementation, a Java VM may not garbage collect or compact it. Like the heap memory, the method area may be of a fixed or variable size. The memory for the method area does not need to be contiguous.

Permanent Generation: The pool containing all the reflective data of the virtual machine itself, such as class and method objects. With Java VMs that use class data sharing, this generation is divided into read-only and read-write areas.
Code Cache: The HotSpot Java VM also includes a code cache, containing memory that is used for compilation and storage of native code.

Here's some documentation on how to use Jconsole.

android: move a view on touch move (ACTION_MOVE)

jQuery UI DatePicker to show month year only

@Ben Koehler, that's prefect! I made a minor modification so that using a single instance of the date picker more than once works as expected. Without this modification the date is parsed incorrectly and the previously selected date is not highlighted.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.1/jquery.js"></script>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.7.2/jquery-ui.min.js"></script>
    <link rel="stylesheet" type="text/css" media="screen" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.7.2/themes/base/jquery-ui.css">
    <script type="text/javascript">
    $(function() {
        $('.date-picker').datepicker( {
            changeMonth: true,
            changeYear: true,
            showButtonPanel: true,
            dateFormat: 'MM yy',
            onClose: function(dateText, inst) { 
                var month = $("#ui-datepicker-div .ui-datepicker-month :selected").val();
                var year = $("#ui-datepicker-div .ui-datepicker-year :selected").val();
                $(this).datepicker('setDate', new Date(year, month, 1));
            },
            beforeShow : function(input, inst) {
                var datestr;
                if ((datestr = $(this).val()).length > 0) {
                    year = datestr.substring(datestr.length-4, datestr.length);
                    month = jQuery.inArray(datestr.substring(0, datestr.length-5), $(this).datepicker('option', 'monthNamesShort'));
                    $(this).datepicker('option', 'defaultDate', new Date(year, month, 1));
                    $(this).datepicker('setDate', new Date(year, month, 1));
                }
            }
        });
    });
    </script>
    <style>
    .ui-datepicker-calendar {
        display: none;
        }
    </style>
</head>
<body>
    <label for="startDate">Date :</label>
    <input name="startDate" id="startDate" class="date-picker" />
</body>
</html>

jQuery calculate sum of values in all text fields

A tad more generic copy/paste function for your project.

sumjq = function(selector) {
    var sum = 0;
    $(selector).each(function() {
        sum += Number($(this).text());
    });
    return sum;
}

console.log(sumjq('.price'));

Descending order by date filter in AngularJs

In my case, the orderBy is determined by a select box. I prefer Ludwig's response because you can set the sort direction in the select options as such:

        $scope.options = [
            { label: 'Title', value: 'title' },
            { label: 'Newest', value: '-publish_date' },
            { label: 'Featured', value: '-featured' }
        ];

markup:

<select ng-model="orderProp" ng-options="opt as opt.label for opt in options"></select>
<ul>
    <li ng-repeat="item in items | orderBy:orderProp.value"></li>
</ul>

Redirect using AngularJS

With an example of the not-working code, it will be easy to answer this question, but with this information the best that I can think is that you are calling the $location.path outside of the AngularJS digest.

Try doing this on the directive scope.$apply(function() { $location.path("/route"); });

How to style HTML5 range input to have different color before and after slider?

Building on top of @dargue3's answer, if you want the thumb to be larger than the track, you want to fully take advantage of the <input type="range" /> element and go cross browser, you need a little extra lines of JS & CSS.

On Chrome/Mozilla you can use the linear-gradient technique, but you need to adjust the ratio based on the min, max, value attributes as mentioned here by @Attila O.. You need to make sure you are not applying this on Edge, otherwise the thumb is not displayed. @Geoffrey Lalloué explains this in more detail here.

Another thing worth mentioning, is that you need to adjust the rangeEl.style.height = "20px"; on IE/Older. Simply put this is because in this case "the height is not applied to the track but rather the whole input including the thumb". fiddle

_x000D_

/**_x000D_
 * Sniffs for Older Edge or IE,_x000D_
 * more info here:_x000D_
 * https://stackoverflow.com/q/31721250/3528132_x000D_
 */_x000D_
function isOlderEdgeOrIE() {_x000D_
  return (_x000D_
    window.navigator.userAgent.indexOf("MSIE ") > -1 ||_x000D_
    !!navigator.userAgent.match(/Trident.*rv\:11\./) ||_x000D_
    window.navigator.userAgent.indexOf("Edge") > -1_x000D_
  );_x000D_
}_x000D_
_x000D_
function valueTotalRatio(value, min, max) {_x000D_
  return ((value - min) / (max - min)).toFixed(2);_x000D_
}_x000D_
_x000D_
function getLinearGradientCSS(ratio, leftColor, rightColor) {_x000D_
  return [_x000D_
    '-webkit-gradient(',_x000D_
    'linear, ',_x000D_
    'left top, ',_x000D_
    'right top, ',_x000D_
    'color-stop(' + ratio + ', ' + leftColor + '), ',_x000D_
    'color-stop(' + ratio + ', ' + rightColor + ')',_x000D_
    ')'_x000D_
  ].join('');_x000D_
}_x000D_
_x000D_
function updateRangeEl(rangeEl) {_x000D_
  var ratio = valueTotalRatio(rangeEl.value, rangeEl.min, rangeEl.max);_x000D_
_x000D_
  rangeEl.style.backgroundImage = getLinearGradientCSS(ratio, '#919e4b', '#c5c5c5');_x000D_
}_x000D_
_x000D_
function initRangeEl() {_x000D_
  var rangeEl = document.querySelector('input[type=range]');_x000D_
  var textEl = document.querySelector('input[type=text]');_x000D_
_x000D_
  /**_x000D_
   * IE/Older Edge FIX_x000D_
   * On IE/Older Edge the height of the <input type="range" />_x000D_
   * is the whole element as oposed to Chrome/Moz_x000D_
   * where the height is applied to the track._x000D_
   *_x000D_
   */_x000D_
  if (isOlderEdgeOrIE()) {_x000D_
    rangeEl.style.height = "20px";_x000D_
    // IE 11/10 fires change instead of input_x000D_
    // https://stackoverflow.com/a/50887531/3528132_x000D_
    rangeEl.addEventListener("change", function(e) {_x000D_
      textEl.value = e.target.value;_x000D_
    });_x000D_
    rangeEl.addEventListener("input", function(e) {_x000D_
      textEl.value = e.target.value;_x000D_
    });_x000D_
  } else {_x000D_
    updateRangeEl(rangeEl);_x000D_
    rangeEl.addEventListener("input", function(e) {_x000D_
      updateRangeEl(e.target);_x000D_
      textEl.value = e.target.value;_x000D_
    });_x000D_
  }_x000D_
}_x000D_
_x000D_
initRangeEl();

_x000D_

input[type="range"] {_x000D_
  -webkit-appearance: none;_x000D_
  -moz-appearance: none;_x000D_
  width: 300px;_x000D_
  height: 5px;_x000D_
  padding: 0;_x000D_
  border-radius: 2px;_x000D_
  outline: none;_x000D_
  cursor: pointer;_x000D_
}_x000D_
_x000D_
_x000D_
/*Chrome thumb*/_x000D_
_x000D_
input[type="range"]::-webkit-slider-thumb {_x000D_
  -webkit-appearance: none;_x000D_
  -moz-appearance: none;_x000D_
  -webkit-border-radius: 5px;_x000D_
  /*16x16px adjusted to be same as 14x14px on moz*/_x000D_
  height: 16px;_x000D_
  width: 16px;_x000D_
  border-radius: 5px;_x000D_
  background: #e7e7e7;_x000D_
  border: 1px solid #c5c5c5;_x000D_
}_x000D_
_x000D_
_x000D_
/*Mozilla thumb*/_x000D_
_x000D_
input[type="range"]::-moz-range-thumb {_x000D_
  -webkit-appearance: none;_x000D_
  -moz-appearance: none;_x000D_
  -moz-border-radius: 5px;_x000D_
  height: 14px;_x000D_
  width: 14px;_x000D_
  border-radius: 5px;_x000D_
  background: #e7e7e7;_x000D_
  border: 1px solid #c5c5c5;_x000D_
}_x000D_
_x000D_
_x000D_
/*IE & Edge input*/_x000D_
_x000D_
input[type=range]::-ms-track {_x000D_
  width: 300px;_x000D_
  height: 6px;_x000D_
  /*remove bg colour from the track, we'll use ms-fill-lower and ms-fill-upper instead */_x000D_
  background: transparent;_x000D_
  /*leave room for the larger thumb to overflow with a transparent border */_x000D_
  border-color: transparent;_x000D_
  border-width: 2px 0;_x000D_
  /*remove default tick marks*/_x000D_
  color: transparent;_x000D_
}_x000D_
_x000D_
_x000D_
/*IE & Edge thumb*/_x000D_
_x000D_
input[type=range]::-ms-thumb {_x000D_
  height: 14px;_x000D_
  width: 14px;_x000D_
  border-radius: 5px;_x000D_
  background: #e7e7e7;_x000D_
  border: 1px solid #c5c5c5;_x000D_
}_x000D_
_x000D_
_x000D_
/*IE & Edge left side*/_x000D_
_x000D_
input[type=range]::-ms-fill-lower {_x000D_
  background: #919e4b;_x000D_
  border-radius: 2px;_x000D_
}_x000D_
_x000D_
_x000D_
/*IE & Edge right side*/_x000D_
_x000D_
input[type=range]::-ms-fill-upper {_x000D_
  background: #c5c5c5;_x000D_
  border-radius: 2px;_x000D_
}_x000D_
_x000D_
_x000D_
/*IE disable tooltip*/_x000D_
_x000D_
input[type=range]::-ms-tooltip {_x000D_
  display: none;_x000D_
}_x000D_
_x000D_
input[type="text"] {_x000D_
  border: none;_x000D_
}

_x000D_

<input type="range" value="80" min="10" max="100" step="1" />_x000D_
<input type="text" value="80" size="3" />

_x000D_

Grant all on a specific schema in the db to a group role in PostgreSQL

My answer is similar to this one on ServerFault.com.

To Be Conservative

If you want to be more conservative than granting "all privileges", you might want to try something more like these.

GRANT SELECT, INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA public TO some_user_;
GRANT EXECUTE ON ALL FUNCTIONS IN SCHEMA public TO some_user_;

The use of public there refers to the name of the default schema created for every new database/catalog. Replace with your own name if you created a schema.

Access to the Schema

To access a schema at all, for any action, the user must be granted "usage" rights. Before a user can select, insert, update, or delete, a user must first be granted "usage" to a schema.

You will not notice this requirement when first using Postgres. By default every database has a first schema named public. And every user by default has been automatically been granted "usage" rights to that particular schema. When adding additional schema, then you must explicitly grant usage rights.

GRANT USAGE ON SCHEMA some_schema_ TO some_user_ ;

Excerpt from the Postgres doc:

For schemas, allows access to objects contained in the specified schema (assuming that the objects' own privilege requirements are also met). Essentially this allows the grantee to "look up" objects within the schema. Without this permission, it is still possible to see the object names, e.g. by querying the system tables. Also, after revoking this permission, existing backends might have statements that have previously performed this lookup, so this is not a completely secure way to prevent object access.

For more discussion see the Question, What GRANT USAGE ON SCHEMA exactly do?. Pay special attention to the Answer by Postgres expert Craig Ringer.

Existing Objects Versus Future

These commands only affect existing objects. Tables and such you create in the future get default privileges until you re-execute those lines above. See the other answer by Erwin Brandstetter to change the defaults thereby affecting future objects.

How can I send an inner <div> to the bottom of its parent <div>?

<div style="width: 200px; height: 150px; border: 1px solid black;position:relative">
    <div style="width: 100%; height: 50px; border: 1px solid red;position:absolute;bottom:0">
    </div>
</div>

Display current time in 12 hour format with AM/PM

To put your current mobile date and time format in

Feb 9, 2018 10:36:59 PM

Date date = new Date();
 String stringDate = DateFormat.getDateTimeInstance().format(date);

you can show it to your Activity, Fragment, CardView, ListView anywhere by using TextView

` TextView mDateTime;

  mDateTime=findViewById(R.id.Your_TextViewId_Of_XML);

  Date date = new Date();
  String mStringDate = DateFormat.getDateTimeInstance().format(date);
  mDateTime.setText("My Device Current Date and Time is:"+date);

  `

How to change int into int64?

This is probably obvious, but simplest:

i64 := int64(23)

Total number of items defined in an enum

You can use the static method Enum.GetNames which returns an array representing the names of all the items in the enum. The length property of this array equals the number of items defined in the enum

var myEnumMemberCount = Enum.GetNames(typeof(MyEnum)).Length;

the MySQL service on local computer started and then stopped

Rename or delete the folder under,

C:\ProgramData\MySQL\MySQL Server 5.7

folder name change as per your MYSQL version number.

Sourcetree - undo unpushed commits

If you want to delete a commit you can do it as part of an interactive rebase. But do it with caution, so you don't end up messing up your repo.

In Sourcetree:

Right click a commit that's older than the one you want to delete, and choose "Rebase children of xxxx interactively...". The one you click will be your "base" and you can make changes to every commit made after that one.

In the new window, select the commit you want gone, and press the "Delete"-button at the bottom, or right click the commit and click "Delete commit".
List item
Click "OK" (or "Cancel" if you want to abort).

Check out this Atlassian blog post for more on interactive rebasing in Sourcetree.

How to set the style -webkit-transform dynamically using JavaScript?

Here are the JavaScript notations for most common vendors:

webkitProperty
MozProperty
msProperty
OProperty
property

I reset inline transform styles like:

element.style.webkitTransform = "";
element.style.MozTransform = "";
element.style.msTransform = "";
element.style.OTransform = "";
element.style.transform = "";

And like this using jQuery:

$(element).css({
    "webkitTransform":"",
    "MozTransform":"",
    "msTransform":"",
    "OTransform":"",
    "transform":""
});

See blog post Coding Vendor Prefixes with JavaScript (2012-03-21).

Apply style to parent if it has child with css

It's not possible with CSS3. There is a proposed CSS4 selector, $, to do just that, which could look like this (Selecting the li element):

ul $li ul.sub { ... }

See the list of CSS4 Selectors here.

As an alternative, with jQuery, a one-liner you could make use of would be this:

$('ul li:has(ul.sub)').addClass('has_sub');

You could then go ahead and style the li.has_sub in your CSS.

How to do SVN Update on my project using the command line

svn update /path/to/working/copy

If subversion is not in your PATH, then of course

/path/to/subversion/svn update /path/to/working/copy

or if you are in the current root directory of your svn repo (it contains a .svn subfolder), it's as simple as

svn update

How do I make an Event in the Usercontrol and have it handled in the Main Form?

Try mapping it. Try placing this code in your UserControl:

public event EventHandler ValueChanged {
  add { numericUpDown1.ValueChanged += value; }
  remove { numericUpDown1.ValueChanged -= value; }
}

then your UserControl will have the ValueChanged event you normally see with the NumericUpDown control.

Detect current device with UI_USER_INTERFACE_IDIOM() in Swift

Try adding an extension like this:

    public extension UIDevice {

    var modelName: String {
        var systemInfo = utsname()
        uname(&systemInfo)
        let machineMirror = Mirror(reflecting: systemInfo.machine)
        let identifier = machineMirror.children.reduce("") { identifier, element in
            guard let value = element.value as? Int8 where value != 0 else { return identifier }
            return identifier + String(UnicodeScalar(UInt8(value)))
        }

        switch identifier {
        case "iPod5,1":                                 return "iPod Touch 5"
        case "iPod7,1":                                 return "iPod Touch 6"
        case "iPhone3,1", "iPhone3,2", "iPhone3,3":     return "iPhone 4"
        case "iPhone4,1":                               return "iPhone 4s"
        case "iPhone5,1", "iPhone5,2":                  return "iPhone 5"
        case "iPhone5,3", "iPhone5,4":                  return "iPhone 5c"
        case "iPhone6,1", "iPhone6,2":                  return "iPhone 5s"
        case "iPhone7,2":                               return "iPhone 6"
        case "iPhone7,1":                               return "iPhone 6 Plus"
        case "iPhone8,1":                               return "iPhone 6s"
        case "iPhone8,2":                               return "iPhone 6s Plus"
        case "iPhone9,1", "iPhone9,3":                  return "iPhone 7"
        case "iPhone9,2", "iPhone9,4":                  return "iPhone 7 Plus"
        case "iPhone8,4":                               return "iPhone SE"
        case "iPad2,1", "iPad2,2", "iPad2,3", "iPad2,4":return "iPad 2"
        case "iPad3,1", "iPad3,2", "iPad3,3":           return "iPad 3"
        case "iPad3,4", "iPad3,5", "iPad3,6":           return "iPad 4"
        case "iPad4,1", "iPad4,2", "iPad4,3":           return "iPad Air"
        case "iPad5,3", "iPad5,4":                      return "iPad Air 2"
        case "iPad2,5", "iPad2,6", "iPad2,7":           return "iPad Mini"
        case "iPad4,4", "iPad4,5", "iPad4,6":           return "iPad Mini 2"
        case "iPad4,7", "iPad4,8", "iPad4,9":           return "iPad Mini 3"
        case "iPad5,1", "iPad5,2":                      return "iPad Mini 4"
        case "iPad6,3", "iPad6,4", "iPad6,7", "iPad6,8":return "iPad Pro"
        case "AppleTV5,3":                              return "Apple TV"
        case "i386", "x86_64":                          return "Simulator"
        default:                                        return identifier
        }
    }

}

This is how you will use it:

let modelName = UIDevice.currentDevice().modelName

EDIT For simulator, you can try a solution here

how to set length of an column in hibernate with maximum length

if your column is varchar use annotation length

@Column(length = 255)

or use another column type

@Column(columnDefinition="TEXT")

Changing directory in Google colab (breaking out of the python interpreter)

If you want to use the cd or ls functions , you need proper identifiers before the function names ( % and ! respectively) use %cd and !ls to navigate

!ls    # to find the directory you're in ,
%cd ./samplefolder  #if you wanna go into a folder (say samplefolder)

or if you wanna go out of the current folder

%cd ../

and then navigate to the required folder/file accordingly

Can't Load URL: The domain of this URL isn't included in the app's domains

I had the same problem, and it came from a wrong client_id / Facebook App ID.

Did you switch your Facebook app to "public" or "online ? When you do so, Facebook creates a new app with a new App ID.

You can compare the "client_id" parameter value in the url with the one in your Facebook dashboard.

Also Make sure your app is public. Click on + Add product Now go to products => Facebook Login Now do the following:

Valid OAuth redirect URIs : example.com/

failed to open stream: No such file or directory in

include() needs a full file path, relative to the file system's root directory.

This should work:

 include_once("C:/xampp/htdocs/PoliticalForum/headerSite.php");

Shared-memory objects in multiprocessing

I run into the same problem and wrote a little shared-memory utility class to work around it.

I'm using multiprocessing.RawArray (lockfree), and also the access to the arrays is not synchronized at all (lockfree), be careful not to shoot your own feet.

With the solution I get speedups by a factor of approx 3 on a quad-core i7.

Here's the code: Feel free to use and improve it, and please report back any bugs.

'''
Created on 14.05.2013

@author: martin
'''

import multiprocessing
import ctypes
import numpy as np

class SharedNumpyMemManagerError(Exception):
    pass

'''
Singleton Pattern
'''
class SharedNumpyMemManager:    

    _initSize = 1024

    _instance = None

    def __new__(cls, *args, **kwargs):
        if not cls._instance:
            cls._instance = super(SharedNumpyMemManager, cls).__new__(
                                cls, *args, **kwargs)
        return cls._instance        

    def __init__(self):
        self.lock = multiprocessing.Lock()
        self.cur = 0
        self.cnt = 0
        self.shared_arrays = [None] * SharedNumpyMemManager._initSize

    def __createArray(self, dimensions, ctype=ctypes.c_double):

        self.lock.acquire()

        # double size if necessary
        if (self.cnt >= len(self.shared_arrays)):
            self.shared_arrays = self.shared_arrays + [None] * len(self.shared_arrays)

        # next handle
        self.__getNextFreeHdl()        

        # create array in shared memory segment
        shared_array_base = multiprocessing.RawArray(ctype, np.prod(dimensions))

        # convert to numpy array vie ctypeslib
        self.shared_arrays[self.cur] = np.ctypeslib.as_array(shared_array_base)

        # do a reshape for correct dimensions            
        # Returns a masked array containing the same data, but with a new shape.
        # The result is a view on the original array
        self.shared_arrays[self.cur] = self.shared_arrays[self.cnt].reshape(dimensions)

        # update cnt
        self.cnt += 1

        self.lock.release()

        # return handle to the shared memory numpy array
        return self.cur

    def __getNextFreeHdl(self):
        orgCur = self.cur
        while self.shared_arrays[self.cur] is not None:
            self.cur = (self.cur + 1) % len(self.shared_arrays)
            if orgCur == self.cur:
                raise SharedNumpyMemManagerError('Max Number of Shared Numpy Arrays Exceeded!')

    def __freeArray(self, hdl):
        self.lock.acquire()
        # set reference to None
        if self.shared_arrays[hdl] is not None: # consider multiple calls to free
            self.shared_arrays[hdl] = None
            self.cnt -= 1
        self.lock.release()

    def __getArray(self, i):
        return self.shared_arrays[i]

    @staticmethod
    def getInstance():
        if not SharedNumpyMemManager._instance:
            SharedNumpyMemManager._instance = SharedNumpyMemManager()
        return SharedNumpyMemManager._instance

    @staticmethod
    def createArray(*args, **kwargs):
        return SharedNumpyMemManager.getInstance().__createArray(*args, **kwargs)

    @staticmethod
    def getArray(*args, **kwargs):
        return SharedNumpyMemManager.getInstance().__getArray(*args, **kwargs)

    @staticmethod    
    def freeArray(*args, **kwargs):
        return SharedNumpyMemManager.getInstance().__freeArray(*args, **kwargs)

# Init Singleton on module load
SharedNumpyMemManager.getInstance()

if __name__ == '__main__':

    import timeit

    N_PROC = 8
    INNER_LOOP = 10000
    N = 1000

    def propagate(t):
        i, shm_hdl, evidence = t
        a = SharedNumpyMemManager.getArray(shm_hdl)
        for j in range(INNER_LOOP):
            a[i] = i

    class Parallel_Dummy_PF:

        def __init__(self, N):
            self.N = N
            self.arrayHdl = SharedNumpyMemManager.createArray(self.N, ctype=ctypes.c_double)            
            self.pool = multiprocessing.Pool(processes=N_PROC)

        def update_par(self, evidence):
            self.pool.map(propagate, zip(range(self.N), [self.arrayHdl] * self.N, [evidence] * self.N))

        def update_seq(self, evidence):
            for i in range(self.N):
                propagate((i, self.arrayHdl, evidence))

        def getArray(self):
            return SharedNumpyMemManager.getArray(self.arrayHdl)

    def parallelExec():
        pf = Parallel_Dummy_PF(N)
        print(pf.getArray())
        pf.update_par(5)
        print(pf.getArray())

    def sequentialExec():
        pf = Parallel_Dummy_PF(N)
        print(pf.getArray())
        pf.update_seq(5)
        print(pf.getArray())

    t1 = timeit.Timer("sequentialExec()", "from __main__ import sequentialExec")
    t2 = timeit.Timer("parallelExec()", "from __main__ import parallelExec")

    print("Sequential: ", t1.timeit(number=1))    
    print("Parallel: ", t2.timeit(number=1))

Android check permission for LocationManager

if you are working on dynamic permissions and any permission like ACCESS_FINE_LOCATION,ACCESS_COARSE_LOCATION giving error "cannot resolve method PERMISSION_NAME" in this case write you code with permission name and then rebuild your project this will regenerate the manifest(Manifest.permission) file.

How to parse a JSON file in swift?

Using ObjectMapper framework

if let path = Bundle(for: BPPView.self).path(forResource: jsonFileName, ofType: "json") {
    do {
        let data = try Data(contentsOf: URL(fileURLWithPath: path), options: NSData.ReadingOptions.mappedIfSafe)
        let json = try JSONSerialization.jsonObject(with: data, options: .allowFragments)
        self.levels = Mapper<Level>().mapArray(JSONArray: (json as! [[String : Any]]))!
        print(levels.count)
    } catch let error as NSError {
        print(error.localizedDescription)
    }
} else {
    print("Invalid filename/path.")
}

Before you should prepare the set of appropriate :Mappable objects to parse into

import UIKit 
import ObjectMapper
class Level: Mappable {
var levelName = ""
var levelItems = [LevelItem]()

required init?(map: Map) {

}

// Mappable
func mapping(map: Map) {
    levelName <- map["levelName"]
    levelItems <- map["levelItems"]
}

 import UIKit 
import ObjectMapper 
class LevelItem: Mappable {
var frontBackSide = BPPFrontBack.Undefined
var fullImageName = ""
var fullImageSelectedName = ""
var bodyParts = [BodyPart]()

required init?(map: Map) {

}

// Mappable
func mapping(map: Map) {
    frontBackSide <- map["frontBackSide"]
    fullImageName <- map["fullImageName"]
    fullImageSelectedName <- map["fullImageSelectedName"]
    bodyParts <- map["bodyParts"]
}}

Is background-color:none valid CSS?

.class {
    background-color:none;
}

This is not a valid property. W3C validator will display following error:

Value Error : background-color none is not a background-color value : none

transparent may have been selected as better term instead of 0 or none values during the development of specification of CSS.

RHEL 6 - how to install 'GLIBC_2.14' or 'GLIBC_2.15'?

download rpm packages and run the following command:

rpm -Uvh glibc-2.15-60.el6.x86_64.rpm \
glibc-common-2.15-60.el6.x86_64.rpm \
glibc-devel-2.15-60.el6.x86_64.rpm \
glibc-headers-2.15-60.el6.x86_64.rpm

Elegant ways to support equivalence ("equality") in Python classes

The way you describe is the way I've always done it. Since it's totally generic, you can always break that functionality out into a mixin class and inherit it in classes where you want that functionality.

class CommonEqualityMixin(object):

    def __eq__(self, other):
        return (isinstance(other, self.__class__)
            and self.__dict__ == other.__dict__)

    def __ne__(self, other):
        return not self.__eq__(other)

class Foo(CommonEqualityMixin):

    def __init__(self, item):
        self.item = item

Locking a file in Python

The other solutions cite a lot of external code bases. If you would prefer to do it yourself, here is some code for a cross-platform solution that uses the respective file locking tools on Linux / DOS systems.

try:
    # Posix based file locking (Linux, Ubuntu, MacOS, etc.)
    #   Only allows locking on writable files, might cause
    #   strange results for reading.
    import fcntl, os
    def lock_file(f):
        if f.writable(): fcntl.lockf(f, fcntl.LOCK_EX)
    def unlock_file(f):
        if f.writable(): fcntl.lockf(f, fcntl.LOCK_UN)
except ModuleNotFoundError:
    # Windows file locking
    import msvcrt, os
    def file_size(f):
        return os.path.getsize( os.path.realpath(f.name) )
    def lock_file(f):
        msvcrt.locking(f.fileno(), msvcrt.LK_RLCK, file_size(f))
    def unlock_file(f):
        msvcrt.locking(f.fileno(), msvcrt.LK_UNLCK, file_size(f))


# Class for ensuring that all file operations are atomic, treat
# initialization like a standard call to 'open' that happens to be atomic.
# This file opener *must* be used in a "with" block.
class AtomicOpen:
    # Open the file with arguments provided by user. Then acquire
    # a lock on that file object (WARNING: Advisory locking).
    def __init__(self, path, *args, **kwargs):
        # Open the file and acquire a lock on the file before operating
        self.file = open(path,*args, **kwargs)
        # Lock the opened file
        lock_file(self.file)

    # Return the opened file object (knowing a lock has been obtained).
    def __enter__(self, *args, **kwargs): return self.file

    # Unlock the file and close the file object.
    def __exit__(self, exc_type=None, exc_value=None, traceback=None):        
        # Flush to make sure all buffered contents are written to file.
        self.file.flush()
        os.fsync(self.file.fileno())
        # Release the lock on the file.
        unlock_file(self.file)
        self.file.close()
        # Handle exceptions that may have come up during execution, by
        # default any exceptions are raised to the user.
        if (exc_type != None): return False
        else:                  return True

Now, AtomicOpen can be used in a with block where one would normally use an open statement.

WARNINGS:

If running on Windows and Python crashes before exit is called, I'm not sure what the lock behavior would be.
The locking provided here is advisory, not absolute. All potentially competing processes must use the "AtomicOpen" class.
As of (Nov 9th, 2020) this code only locks writable files on Posix systems. At some point after the posting and before this date, it became illegal to use the fcntl.lock on read-only files.

How do I pass parameters into a PHP script through a webpage?

$argv[0]; // the script name
$argv[1]; // the first parameter
$argv[2]; // the second parameter

If you want to all the script to run regardless of where you call it from (command line or from the browser) you'll want something like the following:

<?php
if ($_GET) {
    $argument1 = $_GET['argument1'];
    $argument2 = $_GET['argument2'];
} else {
    $argument1 = $argv[1];
    $argument2 = $argv[2];
}
?>

To call from command line chmod 755 /var/www/webroot/index.php and use

/usr/bin/php /var/www/webroot/index.php arg1 arg2

To call from the browser, use

http://www.mydomain.com/index.php?argument1=arg1&argument2=arg2

How do I search for an object by its ObjectId in the mongo console?

I think you better write something like this:

db.getCollection('Blog').find({"_id":ObjectId("58f6724e97990e9de4f17c23")})

White space showing up on right side of page when background image should extend full length of page

The problem is in the file :

style.css - line 721

#sub_footer {
    background: url("../images/exterior/sub_footer.png") repeat-x;
    background: -moz-linear-gradient(0% 100% 90deg,#102c40, #091925);
    background: -webkit-gradient(linear, 0% 0%, 0% 100%, from(#091925), to(#102c40));
    -moz-box-shadow: 3px 3px 4px #999999;
    -webkit-box-shadow: 3px 3px 4px #999999;
    box-shadow: 3px 3px 4px #999999;
    padding-top:10px;
    font-size:9px;
    min-height:40px;
}

remove the lines :

-moz-box-shadow: 3px 3px 4px #999999;
-webkit-box-shadow: 3px 3px 4px #999999;
box-shadow: 3px 3px 4px #999999;

This basically gives a shadow gradient only to the footer. In Firefox, it is the first line that is causing the problem.

What is the difference between baud rate and bit rate?

bit rate : no of bits(0 or 1 for binary signal) transmitted per second.

baud rate : no of symbols per second.

A symbol consists of 'n' number of bits.

Baud rate = (bit rate)/n

So baud rate is always less than or equal to bit rate.It is equal when signal is binary.

How to manage exceptions thrown in filters in Spring?

This is my solution by overriding default Spring Boot /error handler

package com.mypackage;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.web.ErrorAttributes;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.util.Assert;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Map;

/**
 * This controller is vital in order to handle exceptions thrown in Filters.
 */
@RestController
@RequestMapping("/error")
public class ErrorController implements org.springframework.boot.autoconfigure.web.ErrorController {

    private final static Logger LOGGER = LoggerFactory.getLogger(ErrorController.class);

    private final ErrorAttributes errorAttributes;

    @Autowired
    public ErrorController(ErrorAttributes errorAttributes) {
        Assert.notNull(errorAttributes, "ErrorAttributes must not be null");
        this.errorAttributes = errorAttributes;
    }

    @Override
    public String getErrorPath() {
        return "/error";
    }

    @RequestMapping
    public ResponseEntity<Map<String, Object>> error(HttpServletRequest aRequest, HttpServletResponse response) {
        RequestAttributes requestAttributes = new ServletRequestAttributes(aRequest);
        Map<String, Object> result =     this.errorAttributes.getErrorAttributes(requestAttributes, false);

        Throwable error = this.errorAttributes.getError(requestAttributes);

        ResponseStatus annotation =     AnnotationUtils.getAnnotation(error.getClass(), ResponseStatus.class);
        HttpStatus statusCode = annotation != null ? annotation.value() : HttpStatus.INTERNAL_SERVER_ERROR;

        result.put("status", statusCode.value());
        result.put("error", statusCode.getReasonPhrase());

        LOGGER.error(result.toString());
        return new ResponseEntity<>(result, statusCode) ;
    }

}

How to get the difference between two arrays of objects in JavaScript

If you are willing to use external libraries, You can use _.difference in underscore.js to achieve this. _.difference returns the values from array that are not present in the other arrays.

_.difference([1,2,3,4,5][1,4,10])

==>[2,3,5]

Getting View's coordinates relative to the root layout

This is one solution, though since APIs change over time and there may be other ways of doing it, make sure to check the other answers. One claims to be faster, and another claims to be easier.

private int getRelativeLeft(View myView) {
    if (myView.getParent() == myView.getRootView())
        return myView.getLeft();
    else
        return myView.getLeft() + getRelativeLeft((View) myView.getParent());
}

private int getRelativeTop(View myView) {
    if (myView.getParent() == myView.getRootView())
        return myView.getTop();
    else
        return myView.getTop() + getRelativeTop((View) myView.getParent());
}

Let me know if that works.

It should recursively just add the top and left positions from each parent container. You could also implement it with a Point if you wanted.

Fastest way to flatten / un-flatten nested JSON objects

You can try out the package jpflat.

It flattens, inflates, resolves promises, flattens arrays, has customizable path creation and customizable value serialization.

The reducers and serializers receive the whole path as an array of it's parts, so more complex operations can be done to the path instead of modifying a single key or changing the delimiter.

Json path is the default, hence "jp"flat.

https://www.npmjs.com/package/jpflat

let flatFoo = await require('jpflat').flatten(foo)

How do I print bold text in Python?

Check out colorama. It doesn't necessarily help with bolding... but you can do colorized output on both Windows and Linux, and control the brightness:

from colorama import *
init(autoreset=True)
print Fore.RED + 'some red text'
print Style.BRIGHT + Fore.RED + 'some bright red text'

How to append data to a json file?

You can simply import the data from the source file, read it, and save what you want to append to a variable. Then open the destination file, assign the list data inside to a new variable (presumably this will all be valid JSON), then use the 'append' function on this list variable and append the first variable to it. Viola, you have appended to the JSON list. Now just overwrite your destination file with the newly appended list (as JSON).

The 'a' mode in your 'open' function will not work here because it will just tack everything on to the end of the file, which will make it non-valid JSON format.

Is there a REAL performance difference between INT and VARCHAR primary keys?

As for Primary Key, whatever physically makes a row unique should be determined as the primary key.

For a reference as a foreign key, using an auto incrementing integer as a surrogate is a nice idea for two main reasons.
- First, there's less overhead incurred in the join usually.
- Second, if you need to update the table that contains the unique varchar then the update has to cascade down to all the child tables and update all of them as well as the indexes, whereas with the int surrogate, it only has to update the master table and it's indexes.

The drawaback to using the surrogate is that you could possibly allow changing of the meaning of the surrogate:

ex.
id value
1 A
2 B
3 C

Update 3 to D
id value
1 A
2 B
3 D

Update 2 to C
id value
1 A
2 C
3 D

Update 3 to B
id value
1 A
2 C
3 B

It all depends on what you really need to worry about in your structure and what means most.

'namespace' but is used like a 'type'

if the error is

Line 26:
Line 27: @foreach (Customers customer in Model) Line 28: { Line 29:

give the full name space
like @foreach (Start.Models.customer customer in Model)

Custom HTTP Authorization Header

No, that is not a valid production according to the "credentials" definition in RFC 2617. You give a valid auth-scheme, but auth-param values must be of the form token "=" ( token | quoted-string ) (see section 1.2), and your example doesn't use "=" that way.

Adding and removing extensionattribute to AD object

Set-ADUser -Identity anyUser -Replace @{extensionAttribute4="myString"}

This is also usefull

Error message "unreported exception java.io.IOException; must be caught or declared to be thrown"

Exceptions bubble up the stack. If a caller calls a method that throws a checked exception, like IOException, it must also either catch the exception, or itself throw it.

In the case of the first block:

filecontent()
{
    setGUI();
    setRegister();
    showfile();
    setTitle("FileData");
    setVisible(true);
    setSize(300, 300);

    /*
        addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent we)
            {
                System.exit(0);
            }
        });
    */
}

You would have to include a try catch block:

filecontent()
{
    setGUI();
    setRegister();
    try {
        showfile();
    }
    catch (IOException e) {
        // Do something here
    }
    setTitle("FileData");
    setVisible(true);
    setSize(300, 300);

    /*
        addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent we)
            {
                System.exit(0);
            }
        });
    */
}

In the case of the second:

public void actionPerformed(ActionEvent ae)
{
    if (ae.getSource() == submit)
    {
        showfile();
    }
}

You cannot throw IOException from this method as its signature is determined by the interface, so you must catch the exception within:

public void actionPerformed(ActionEvent ae)
{
    if(ae.getSource()==submit)
    {
        try {
            showfile();
        }
        catch (IOException e) {
            // Do something here
        }
    }
}

Remember, the showFile() method is throwing the exception; that's what the "throws" keyword indicates that the method may throw that exception. If the showFile() method is throwing, then whatever code calls that method must catch, or themselves throw the exception explicitly by including the same throws IOException addition to the method signature, if it's permitted.

If the method is overriding a method signature defined in an interface or superclass that does not also declare that the method may throw that exception, you cannot declare it to throw an exception.

Regex for password must contain at least eight characters, at least one number and both lower and uppercase letters and special characters

I've found many problems here, so I made my own.

Here it is in all it's glory, with tests:

^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*([^a-zA-Z\d\s])).{9,}$

https://regex101.com/r/DCRR65/4/tests

Things to look out for:

doesn't use \w because that includes _, which I'm testing for.
I've had lots of troubles matching symbols, without matching the end of the line.
Doesn't specify symbols specifically, this is also because different locales may have different symbols on their keyboards that they may want to use.

What is the official "preferred" way to install pip and virtualenv systemwide?

On Ubuntu 12.04 I've had good luck just using the package manager:

sudo apt-get install python-pip virtualenvwrapper

How to check if there exists a process with a given pid in Python?

mluebke code is not 100% correct; kill() can also raise EPERM (access denied) in which case that obviously means a process exists. This is supposed to work:

(edited as per Jason R. Coombs comments)

import errno
import os

def pid_exists(pid):
    """Check whether pid exists in the current process table.
    UNIX only.
    """
    if pid < 0:
        return False
    if pid == 0:
        # According to "man 2 kill" PID 0 refers to every process
        # in the process group of the calling process.
        # On certain systems 0 is a valid PID but we have no way
        # to know that in a portable fashion.
        raise ValueError('invalid PID 0')
    try:
        os.kill(pid, 0)
    except OSError as err:
        if err.errno == errno.ESRCH:
            # ESRCH == No such process
            return False
        elif err.errno == errno.EPERM:
            # EPERM clearly means there's a process to deny access to
            return True
        else:
            # According to "man 2 kill" possible error values are
            # (EINVAL, EPERM, ESRCH)
            raise
    else:
        return True

You can't do this on Windows unless you use pywin32, ctypes or a C extension module. If you're OK with depending from an external lib you can use psutil:

>>> import psutil
>>> psutil.pid_exists(2353)
True

Remove a CLASS for all child elements

You can also do like this :

  $("#table-filters li").parent().find('li').removeClass("active");

How to get process details from its pid

$(form).ajaxSubmit is not a function

this is new function so you have to add other lib file after jQuery lib

<script src="http://malsup.github.com/jquery.form.js"></script>

it will work.. I have tested.. hope it will work for you..

How do you fix the "element not interactable" exception?

It will be better to use xpath

from selenium import webdriver
driver.get('www.example.com')
button = driver.find_element_by_xpath('xpath')
button.click()

How can I get a specific parameter from location.search?

function gup( name ) {
    name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
    var regexS = "[\\?&]"+name+"=([^&#]*)";
    var regex = new RegExp( regexS );
    var results = regex.exec( window.location.href );
    if( results == null )
        return "";
    else
        return results[1];
}
var year = gup("year"); // returns "2008"

C# testing to see if a string is an integer?

I've been coding for about 2 weeks and created a simple logic to validate an integer has been accepted.

    Console.WriteLine("How many numbers do you want to enter?"); // request a number
    string input = Console.ReadLine(); // set the input as a string variable
    int numberTotal; // declare an int variable

    if (!int.TryParse(input, out numberTotal)) // process if input was an invalid number
    {
        while (numberTotal  < 1) // numberTotal is set to 0 by default if no number is entered
        {
            Console.WriteLine(input + " is an invalid number."); // error message
            int.TryParse(Console.ReadLine(), out numberTotal); // allows the user to input another value
        }

    } // this loop will repeat until numberTotal has an int set to 1 or above

you could also use the above in a FOR loop if you prefer by not declaring an action as the third parameter of the loop, such as

    Console.WriteLine("How many numbers do you want to enter?");
    string input2 = Console.ReadLine();

    if (!int.TryParse(input2, out numberTotal2))
    {
        for (int numberTotal2 = 0; numberTotal2 < 1;)
        {
            Console.WriteLine(input2 + " is an invalid number.");
            int.TryParse(Console.ReadLine(), out numberTotal2);
        }

    }

if you don't want a loop, simply remove the entire loop brace

Play infinitely looping video on-load in HTML5

You can do this the following two ways:

1) Using loop attribute in video element (mentioned in the first answer):

2) and you can use the ended media event:

window.addEventListener('load', function(){
    var newVideo = document.getElementById('videoElementId');
    newVideo.addEventListener('ended', function() {
        this.currentTime = 0;
        this.play();
    }, false);

    newVideo.play();

});

Looping Over Result Sets in MySQL

Use cursors.

A cursor can be thought of like a buffered reader, when reading through a document. If you think of each row as a line in a document, then you would read the next line, perform your operations, and then advance the cursor.

Visual Studio Code open tab in new window

On Windows and Linux, press Ctrl+K, then release the keys and press O (the letter O, not Zero).

On macOS, press command+K, then O (without holding command).

This will open the active file tab in a new window/instance.

How to list processes attached to a shared memory segment in linux?

I wrote a tool called who_attach_shm.pl, it parses /proc/[pid]/maps to get the information. you can download it from github

sample output:

shm attach process list, group by shm key
##################################################################

0x2d5feab4:    /home/curu/mem_dumper /home/curu/playd
0x4e47fc6c:    /home/curu/playd
0x77da6cfe:    /home/curu/mem_dumper /home/curu/playd /home/curu/scand

##################################################################
process shm usage
##################################################################
/home/curu/mem_dumper [2]:    0x2d5feab4 0x77da6cfe
/home/curu/playd [3]:    0x2d5feab4 0x4e47fc6c 0x77da6cfe
/home/curu/scand [1]:    0x77da6cfe

How to implement an STL-style iterator and avoid common pitfalls?

Here is sample of raw pointer iterator.

You shouldn't use iterator class to work with raw pointers!

#include <iostream>
#include <vector>
#include <list>
#include <iterator>
#include <assert.h>

template<typename T>
class ptr_iterator
    : public std::iterator<std::forward_iterator_tag, T>
{
    typedef ptr_iterator<T>  iterator;
    pointer pos_;
public:
    ptr_iterator() : pos_(nullptr) {}
    ptr_iterator(T* v) : pos_(v) {}
    ~ptr_iterator() {}

    iterator  operator++(int) /* postfix */         { return pos_++; }
    iterator& operator++()    /* prefix */          { ++pos_; return *this; }
    reference operator* () const                    { return *pos_; }
    pointer   operator->() const                    { return pos_; }
    iterator  operator+ (difference_type v)   const { return pos_ + v; }
    bool      operator==(const iterator& rhs) const { return pos_ == rhs.pos_; }
    bool      operator!=(const iterator& rhs) const { return pos_ != rhs.pos_; }
};

template<typename T>
ptr_iterator<T> begin(T *val) { return ptr_iterator<T>(val); }


template<typename T, typename Tsize>
ptr_iterator<T> end(T *val, Tsize size) { return ptr_iterator<T>(val) + size; }

Raw pointer range based loop workaround. Please, correct me, if there is better way to make range based loop from raw pointer.

template<typename T>
class ptr_range
{
    T* begin_;
    T* end_;
public:
    ptr_range(T* ptr, size_t length) : begin_(ptr), end_(ptr + length) { assert(begin_ <= end_); }
    T* begin() const { return begin_; }
    T* end() const { return end_; }
};

template<typename T>
ptr_range<T> range(T* ptr, size_t length) { return ptr_range<T>(ptr, length); }

And simple test

void DoIteratorTest()
{
    const static size_t size = 10;
    uint8_t *data = new uint8_t[size];
    {
        // Only for iterator test
        uint8_t n = '0';
        auto first = begin(data);
        auto last = end(data, size);
        for (auto it = first; it != last; ++it)
        {
            *it = n++;
        }

        // It's prefer to use the following way:
        for (const auto& n : range(data, size))
        {
            std::cout << " char: " << static_cast<char>(n) << std::endl;
        }
    }
    {
        // Only for iterator test
        ptr_iterator<uint8_t> first(data);
        ptr_iterator<uint8_t> last(first + size);
        std::vector<uint8_t> v1(first, last);

        // It's prefer to use the following way:
        std::vector<uint8_t> v2(data, data + size);
    }
    {
        std::list<std::vector<uint8_t>> queue_;
        queue_.emplace_back(begin(data), end(data, size));
        queue_.emplace_back(data, data + size);
    }
}

SQL Server: how to create a stored procedure

Create this way.

Create procedure dept_count(dept_name varchar(20),d_count integer)
   begin
     select count(*) into d_count
     from instructor
     where instructor.dept_name=dept_count.dept_name
   end

How to close a thread from within?

When you start a thread, it begins executing a function you give it (if you're extending threading.Thread, the function will be run()). To end the thread, just return from that function.

According to this, you can also call thread.exit(), which will throw an exception that will end the thread silently.

MySQL and GROUP_CONCAT() maximum length

Include this setting in xampp my.ini configuration file:

[mysqld]
group_concat_max_len = 1000000

Then restart xampp mysql

Changing an element's ID with jQuery

Your syntax is incorrect, you should pass the value as the second parameter:

jQuery(this).prev("li").attr("id","newId");

Php artisan make:auth command is not defined

If you using >5 version of laravel then you will use.

composer require laravel/ui --dev **or** composer require laravel/ui

And then

php artisan ui:auth

Exception in thread "main" java.util.NoSuchElementException

You close the second Scanner which closes the underlying InputStream, therefore the first Scanner can no longer read from the same InputStream and a NoSuchElementException results.

The solution: For console apps, use a single Scanner to read from System.in.

Aside: As stated already, be aware that Scanner#nextInt does not consume newline characters. Ensure that these are consumed before attempting to call nextLine again by using Scanner#newLine().

See: Do not create multiple buffered wrappers on a single InputStream

What is the difference between gravity and layout_gravity in Android?

gravity: is used for simple views like textview, edittext etc.

layout_gravity: is used for current view only gravity in context of it's relative parent view like linear Layout or FrameLayout to make view in center or any other gravity of its parent.

Best way to convert string to bytes in Python 3?

If you look at the docs for bytes, it points you to bytearray:

bytearray([source[, encoding[, errors]]])

Return a new array of bytes. The bytearray type is a mutable sequence of integers in the range 0 <= x < 256. It has most of the usual methods of mutable sequences, described in Mutable Sequence Types, as well as most methods that the bytes type has, see Bytes and Byte Array Methods.

The optional source parameter can be used to initialize the array in a few different ways:

If it is a string, you must also give the encoding (and optionally, errors) parameters; bytearray() then converts the string to bytes using str.encode().

If it is an integer, the array will have that size and will be initialized with null bytes.

If it is an object conforming to the buffer interface, a read-only buffer of the object will be used to initialize the bytes array.

If it is an iterable, it must be an iterable of integers in the range 0 <= x < 256, which are used as the initial contents of the array.

Without an argument, an array of size 0 is created.

So bytes can do much more than just encode a string. It's Pythonic that it would allow you to call the constructor with any type of source parameter that makes sense.

For encoding a string, I think that some_string.encode(encoding) is more Pythonic than using the constructor, because it is the most self documenting -- "take this string and encode it with this encoding" is clearer than bytes(some_string, encoding) -- there is no explicit verb when you use the constructor.

Edit: I checked the Python source. If you pass a unicode string to bytes using CPython, it calls PyUnicode_AsEncodedString, which is the implementation of encode; so you're just skipping a level of indirection if you call encode yourself.

Also, see Serdalis' comment -- unicode_string.encode(encoding) is also more Pythonic because its inverse is byte_string.decode(encoding) and symmetry is nice.

Gcc error: gcc: error trying to exec 'cc1': execvp: No such file or directory

Make sure your GCC_EXEC_PREFIX(env) is not exported and your PATH is exported to right tool chain.

How does the SQL injection from the "Bobby Tables" XKCD comic work?

Say you naively wrote a student creation method like this:

void createStudent(String name) {
    database.execute("INSERT INTO students (name) VALUES ('" + name + "')");
}

And someone enters the name Robert'); DROP TABLE STUDENTS; --

What gets run on the database is this query:

INSERT INTO students (name) VALUES ('Robert'); DROP TABLE STUDENTS --')

The semicolon ends the insert command and starts another; the -- comments out the rest of the line. The DROP TABLE command is executed...

This is why bind parameters are a good thing.

SQL query to make all data in a column UPPER CASE?

If you want to only update on rows that are not currently uppercase (instead of all rows), you'd need to identify the difference using COLLATE like this:

UPDATE MyTable
SET    MyColumn = UPPER(MyColumn)
WHERE  MyColumn != UPPER(MyColumn) COLLATE Latin1_General_CS_AS

A Bit About Collation

Cases sensitivity is based on your collation settings, and is typically case insensitive by default.

Collation can be set at the Server, Database, Column, or Query Level:

-- Server
SELECT SERVERPROPERTY('COLLATION')
-- Database
SELECT name, collation_name FROM sys.databases
-- Column 
SELECT COLUMN_NAME, COLLATION_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE CHARACTER_SET_NAME IS NOT NULL

Collation Names specify how a string should be encoded and read, for example:

Latin1_General_CI_AS ? Case Insensitive
Latin1_General_CS_AS ? Case Sensitive

Compiling Java 7 code via Maven

You might be specifying a wrong version of java. java -version(in your terminal) to check the version of java you are using. Go to maven-compile-plugin for the latest maven compiler version Your plugin may appear like this if you are using java 6 and the latest version of maven compiler plugin is 3.1

<plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>1.6</source>
                <target>1.6</target>
            </configuration>
        </plugin>

Read and write into a file using VBScript

Don't think so...you can only use openTextFile for reading (1), writing (2), or appending (8). Reference here.

If you were using VB6 instead of VBScript, you could do:

Open "Filename" [For Mode] [AccessRestriction] [LockType] As #FileNumber

Using the Random mode. For example:

Open "C:\New\maddy.txt" For Random As #1

Timer for Python game

Asks you when to stop [seconds]
Adds '0' at starting [1-9]

import time
import sys

stop = int(input('> '))
second = 0
print('> Stopwatch Started.')

while stop > second:
    if second < 9:
        second = second + 1
        time.sleep(1)
        sys.stdout.write('\r> ' + '0' + str(second))
    else:
        second += 1
        time.sleep(1)
        sys.stdout.write('\r' + '> ' + str(second))

print('\n> Stopwatch Stopped.')

Draw a connecting line between two elements

D3 has hundreds of examples, some of which are suitable for this question.

Examples without drag and drop, that are fixed:

Examples without drag and drop, that are interactive:

Examples with dragging and dropping:

This answer is based off of Glenn Dayton's answer.

java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

i too faced the same problem.... and resolved by following the below steps:

RC(right click on web project) --> properties --> Deployment Assembly --> Add --> Java Build Path Entries --> Next --> select jar files which are missing --> next --> finish

Application is running successfully...

Event when window.location.href changes

popstate event:

The popstate event is fired when the active history entry changes. [...] The popstate event is only triggered by doing a browser action such as a click on the back button (or calling history.back() in JavaScript)

So, listening to popstate event and sending a popstate event when using history.pushState() should be enough to take action on href change:

window.addEventListener('popstate', listener);

const pushUrl = (href) => {
  history.pushState({}, '', href);
  window.dispatchEvent(new Event('popstate'));
};

How do operator.itemgetter() and sort() work?

Looks like you're a little bit confused about all that stuff.

operator is a built-in module providing a set of convenient operators. In two words operator.itemgetter(n) constructs a callable that assumes an iterable object (e.g. list, tuple, set) as input, and fetches the n-th element out of it.

So, you can't use key=a[x][1] there, because python has no idea what x is. Instead, you could use a lambda function (elem is just a variable name, no magic there):

a.sort(key=lambda elem: elem[1])

Or just an ordinary function:

def get_second_elem(iterable):
    return iterable[1]

a.sort(key=get_second_elem)

So, here's an important note: in python functions are first-class citizens, so you can pass them to other functions as a parameter.

How does GPS in a mobile phone work exactly?

There's 3 satellites at least that you must be able to receive from of the 24-32 out there, and they each broadcast a time from a synchronized atomic clock. The differences in those times that you receive at any one time tell you how long the broadcast took to reach you, and thus where you are in relation to the satellites. So, it sort of reads from something, but it doesn't connect to that thing. Note that this doesn't tell you your orientation, many GPSes fake that (and speed) by interpolating data points.

If you don't count the cost of the receiver, it's a free service. Apparently there's higher resolution services out there that are restricted to military use. Those are likely a fixed cost for a license to decrypt the signals along with a confidentiality agreement.

Now your device may support GPS tracking, in which case it might communicate, say via GPRS, to a database which will store the location the device has found itself to be at, so that multiple devices may be tracked. That would require some kind of connection.

Maps are either stored on the device or received over a connection. Navigation is computed based on those maps' databases. These likely are a licensed item with a cost associated, though if you use a service like Google Maps they have the license with NAVTEQ and others.

Unit testing with mockito for constructors

I believe, it is not possible to mock constructors using mockito. Instead, I suggest following approach

Class First {

   private Second second;

   public First(int num, String str) {
     if(second== null)
     {
       //when junit runs, you get the mocked object(not null), hence don't 
       //initialize            
       second = new Second(str);
     }
     this.num = num;
   }

   ... // some other methods
}

And, for test:

class TestFirst{
    @InjectMock
    First first;//inject mock the real testable class
    @Mock
    Second second

    testMethod(){

        //now you can play around with any method of the Second class using its 
        //mocked object(second),like:
        when(second.getSomething(String.class)).thenReturn(null);
    }
}

Check whether a string matches a regex in JS

You can try this, it works for me.

 <input type="text"  onchange="CheckValidAmount(this.value)" name="amount" required>

 <script type="text/javascript">
    function CheckValidAmount(amount) {          
       var a = /^(?:\d{1,3}(?:,\d{3})*|\d+)(?:\.\d+)?$/;
       if(amount.match(a)){
           alert("matches");
       }else{
        alert("does not match"); 
       }
    }
</script>

Remove duplicates from an array of objects in JavaScript

This is a generic way of doing this: you pass in a function that tests whether two elements of an array are considered equal. In this case, it compares the values of the name and place properties of the two objects being compared.

ES5 answer

_x000D_

function removeDuplicates(arr, equals) {_x000D_
    var originalArr = arr.slice(0);_x000D_
    var i, len, val;_x000D_
    arr.length = 0;_x000D_
_x000D_
    for (i = 0, len = originalArr.length; i < len; ++i) {_x000D_
        val = originalArr[i];_x000D_
        if (!arr.some(function(item) { return equals(item, val); })) {_x000D_
            arr.push(val);_x000D_
        }_x000D_
    }_x000D_
}_x000D_
_x000D_
function thingsEqual(thing1, thing2) {_x000D_
    return thing1.place === thing2.place_x000D_
        && thing1.name === thing2.name;_x000D_
}_x000D_
_x000D_
var things = [_x000D_
  {place:"here",name:"stuff"},_x000D_
  {place:"there",name:"morestuff"},_x000D_
  {place:"there",name:"morestuff"}_x000D_
];_x000D_
_x000D_
removeDuplicates(things, thingsEqual);_x000D_
console.log(things);

_x000D_

Original ES3 answer

function arrayContains(arr, val, equals) {
    var i = arr.length;
    while (i--) {
        if ( equals(arr[i], val) ) {
            return true;
        }
    }
    return false;
}

function removeDuplicates(arr, equals) {
    var originalArr = arr.slice(0);
    var i, len, j, val;
    arr.length = 0;

    for (i = 0, len = originalArr.length; i < len; ++i) {
        val = originalArr[i];
        if (!arrayContains(arr, val, equals)) {
            arr.push(val);
        }
    }
}

function thingsEqual(thing1, thing2) {
    return thing1.place === thing2.place
        && thing1.name === thing2.name;
}

removeDuplicates(things.thing, thingsEqual);

Initialise a list to a specific length in Python

In a talk about core containers internals in Python at PyCon 2012, Raymond Hettinger is suggesting to use [None] * n to pre-allocate the length you want.

Slides available as PPT or via Google

The whole slide deck is quite interesting. The presentation is available on YouTube, but it doesn't add much to the slides.

Prevent multiple instances of a given app in .NET?

This article simply explains how you can create a windows application with control on the number of its instances or run only single instance. This is very typical need of a business application. There are already lots of other possible solutions to control this.

https://web.archive.org/web/20090205153420/http://www.openwinforms.com/single_instance_application.html

CSS Circular Cropping of Rectangle Image

insert the image and then backhand all you need is:

<style>
img {
  border-radius: 50%;
}
</style>

** the image code will be here automatically**

How to trim a file extension from a String in JavaScript?

If you have to process a variable that contains the complete path (ex.: thePath = "http://stackoverflow.com/directory/subdirectory/filename.jpg") and you want to return just "filename" you can use:

theName = thePath.split("/").slice(-1).join().split(".").shift();

the result will be theName == "filename";

To try it write the following command into the console window of your chrome debugger: window.location.pathname.split("/").slice(-1).join().split(".").shift()

If you have to process just the file name and its extension (ex.: theNameWithExt = "filename.jpg"):

theName = theNameWithExt.split(".").shift();

the result will be theName == "filename", the same as above;

Notes:

The first one is a little bit slower cause performes more operations; but works in both cases, in other words it can extract the file name without extension from a given string that contains a path or a file name with ex. While the second works only if the given variable contains a filename with ext like filename.ext but is a little bit quicker.
Both solutions work for both local and server files;

But I can't say nothing about neither performances comparison with other answers nor for browser or OS compatibility.

working snippet 1: the complete path

_x000D_

var thePath = "http://stackoverflow.com/directory/subdirectory/filename.jpg";_x000D_
theName = thePath.split("/").slice(-1).join().split(".").shift();_x000D_
alert(theName);

_x000D_

working snippet 2: the file name with extension

_x000D_

var theNameWithExt = "filename.jpg";_x000D_
theName = theNameWithExt.split("/").slice(-1).join().split(".").shift();_x000D_
alert(theName);

_x000D_

working snippet 2: the file name with double extension

_x000D_

var theNameWithExt = "filename.tar.gz";_x000D_
theName = theNameWithExt.split("/").slice(-1).join().split(".").shift();_x000D_
alert(theName);

_x000D_

Redirecting 404 error with .htaccess via 301 for SEO etc

You will need to know something about the URLs, like do they have a specific directory or some query string element because you have to match for something. Otherwise you will have to redirect on the 404. If this is what is required then do something like this in your .htaccess:

ErrorDocument 404 /index.php

An error page redirect must be relative to root so you cannot use www.mydomain.com.

If you have a pattern to match too then use 301 instead of 302 because 301 is permanent and 302 is temporary. A 301 will get the old URLs removed from the search engines and the 302 will not.

Mod Rewrite Reference: http://httpd.apache.org/docs/1.3/mod/mod_rewrite.html

What is the pythonic way to detect the last element in a 'for' loop?

I will provide with a more elegant and robust way as follows, using unpacking:

def mark_last(iterable):
    try:
        *init, last = iterable
    except ValueError:  # if iterable is empty
        return

    for e in init:
        yield e, True
    yield last, False

Test:

for a, b in mark_last([1, 2, 3]):
    print(a, b)

The result is:

1 True
2 True
3 False

Why is SQL server throwing this error: Cannot insert the value NULL into column 'id'?

if you can't or don't want to set the autoincrement property of the id, you can set value for the id for each row, like this:

INSERT INTO role (id, name, created)
SELECT 
      (select max(id) from role) + ROW_NUMBER() OVER (ORDER BY name)
    , name
    , created
FROM (
    VALUES 
      ('Content Coordinator', GETDATE())
    , ('Content Viewer', GETDATE())
) AS x(name, created)

How to remove elements from a generic list while iterating over it?

Just wanted to add my 2 cents to this in case this helps anyone, I had a similar problem but needed to remove multiple elements from an array list while it was being iterated over. the highest upvoted answer did it for me for the most part until I ran into errors and realized that the index was greater than the size of the array list in some instances because multiple elements were being removed but the index of the loop didn't keep track of that. I fixed this with a simple check:

ArrayList place_holder = new ArrayList();
place_holder.Add("1");
place_holder.Add("2");
place_holder.Add("3");
place_holder.Add("4");

for(int i = place_holder.Count-1; i>= 0; i--){
    if(i>= place_holder.Count){
        i = place_holder.Count-1; 
    }

// some method that removes multiple elements here
}

Find duplicate records in MongoDB

Use aggregation on name and get name with count > 1:

db.collection.aggregate([
    {"$group" : { "_id": "$name", "count": { "$sum": 1 } } },
    {"$match": {"_id" :{ "$ne" : null } , "count" : {"$gt": 1} } }, 
    {"$project": {"name" : "$_id", "_id" : 0} }
]);

To sort the results by most to least duplicates:

db.collection.aggregate([
    {"$group" : { "_id": "$name", "count": { "$sum": 1 } } },
    {"$match": {"_id" :{ "$ne" : null } , "count" : {"$gt": 1} } }, 
    {"$sort": {"count" : -1} },
    {"$project": {"name" : "$_id", "_id" : 0} }     
]);

To use with another column name than "name", change "$name" to "$column_name"

Initialize a string in C to empty string

Assigning string literals to char array is allowed only during declaration:

char string[] = "";

This declares string as a char array of size 1 and initializes it with \0.

Try this too:

char str1[] = ""; 
char str2[5] = ""; 
printf("%d, %d\n", sizeof(str1), sizeof(str2)); //prints 1, 5

C# : Out of Memory exception

As .Net progresses, so does their ability to add new 32-bit configurations that trips everyone up it seems.

If you are on .Net Framework 4.7.2 do the following:

Go to Project Properties

Build

Uncheck 'prefer 32-bit'

Cheers!

The requested operation cannot be performed on a file with a user-mapped section open

Deleting the obj folder and rebuilding worked for me

What is Linux’s native GUI API?

In Linux the graphical user interface is not a part of the operating system. The graphical user interface found on most Linux desktops is provided by software called the X Window System, which defines a device independent way of dealing with screens, keyboards and pointer devices.

X Window defines a network protocol for communication, and any program that knows how to "speak" this protocol can use it. There is a C library called Xlib that makes it easier to use this protocol, so Xlib is kind of the native GUI API. Xlib is not the only way to access an X Window server; there is also XCB.

Toolkit libraries such as GTK+ (used by GNOME) and Qt (used by KDE), built on top of Xlib, are used because they are easier to program with. For example they give you a consistent look and feel across applications, make it easier to use drag-and-drop, provide components standard to a modern desktop environment, and so on.

How X draws on the screen internally depends on the implementation. X.org has a device independent part and a device dependent part. The former manages screen resources such as windows, while the latter communicates with the graphics card driver, usually a kernel module. The communication may happen over direct memory access or through system calls to the kernel. The driver translates the commands into a form that the hardware on the card understands.

As of 2013, a new window system called Wayland is starting to become usable, and many distributions have said they will at some point migrate to it, though there is still no clear schedule. This system is based on OpenGL/ES API, which means that in the future OpenGL will be the "native GUI API" in Linux. Work is being done to port GTK+ and QT to Wayland, so that current popular applications and desktop systems would need minimal changes. The applications that cannot be ported will be supported through an X11 server, much like OS X supports X11 apps through Xquartz. The GTK+ port is expected to be finished within a year, while Qt 5 already has complete Wayland support.

To further complicate matters, Ubuntu has announced they are developing a new system called Mir because of problems they perceive with Wayland. This window system is also based on the OpenGL/ES API.

Create a new workspace in Eclipse

I use File -> Switch Workspace -> Other... and type in my new workspace name.

New workspace composite screenshot (EDIT: Added the composite screen shot.)

Once in the new workspace, File -> Import... and under General choose "Existing Projects into Workspace. Press the Next button and then Browse for the old projects you would like to import. Check "Copy projects into workspace" to make a copy.

How to convert from []byte to int in Go Programming

If []byte is ASCII byte numbers then first convert the []byte to string and use the strconv package Atoi method which convert string to int.

package main
import (
    "fmt"
    "strconv"
)

func main() {
    byteNumber := []byte("14")
    byteToInt, _ := strconv.Atoi(string(byteNumber))
    fmt.Println(byteToInt)
}

go playground - https://play.golang.org/p/gEzxva8-BGP

Filter Java Stream to 1 and only 1 element

The "escape hatch" operation that lets you do weird things that are not otherwise supported by streams is to ask for an Iterator:

Iterator<T> it = users.stream().filter((user) -> user.getId() < 0).iterator();
if (!it.hasNext()) 
    throw new NoSuchElementException();
else {
    result = it.next();
    if (it.hasNext())
        throw new TooManyElementsException();
}

Guava has a convenience method to take an Iterator and get the only element, throwing if there are zero or multiple elements, which could replace the bottom n-1 lines here.

Get Memory Usage in Android

Check the Debug class. http://developer.android.com/reference/android/os/Debug.html i.e. Debug.getNativeHeapAllocatedSize()

It has methods to get the used native heap, which is i.e. used by external bitmaps in your app. For the heap that the app is using internally, you can see that in the DDMS tool that comes with the Android SDK and is also available via Eclipse.

The native heap + the heap as indicated in the DDMS make up the total heap that your app is allocating.

For CPU usage I'm not sure if there's anything available via API/SDK.

new DateTime() vs default(DateTime)

The answer is no. Keep in mind that in both cases, mdDate.Kind = DateTimeKind.Unspecified.

Therefore it may be better to do the following:

DateTime myDate = new DateTime(1, 1, 1, 0, 0, 0, DateTimeKind.Utc);

The myDate.Kind property is readonly, so it cannot be changed after the constructor is called.

What is difference between mutable and immutable String in java

In Java, all strings are immutable. When you are trying to modify a String, what you are really doing is creating a new one. However, when you use a StringBuilder, you are actually modifying the contents, instead of creating a new one.

How do I start PowerShell from Windows Explorer?

I'm surprised nobody has given this answer, it's the simplest one. (Must be the year.)

Just Shift + right click in Explorer. Then you can "Open PowerShell window here".

It may be set to Command Prompt by default. If so, you can change this in the Windows 10 Settings: go to Personalization -> Taskbar and enable "Replace Command Prompt with Windows PowerShell in the menu when I right-click the start button or press Windows key+X".

Margin-Top not working for span element?

Looks like you missed some options, try to add:

position: relative;
top: 25px;

How to leave space in HTML

As others already answered, $nbsp; will output no-break space character. Here is w3 docs for &nbsp and others.

However there is other ways to do it and nowdays i would prefer using CSS stylesheets. There is also w3c tutorials for beginners.

With CSS you can do it like this:

<html>
    <head>
        <title>CSS test</title>
        <style type="text/css">
            p { word-spacing: 40px; }
        </style>
    </head>
    <body>
        <p>Hello World! Enough space between words, what do you think about it?</p>
    </body>
</html>

How can I run code on a background thread on Android?

IF you need to:

execute code on a background Thread
execute code that DOES NOT touch/update the UI
execute (short) code which will take at most a few seconds to complete

THEN use the following clean and efficient pattern which uses AsyncTask:

AsyncTask.execute(new Runnable() {
   @Override
   public void run() {
      //TODO your background code
   }
});

What is the difference between res.end() and res.send()?

I would like to make a little bit more emphasis on some key differences between res.end() & res.send() with respect to response headers and why they are important.

1. res.send() will check the structure of your output and set header information accordingly.

    app.get('/',(req,res)=>{
       res.send('<b>hello</b>');
    });

     app.get('/',(req,res)=>{
         res.send({msg:'hello'});
     });

Where with res.end() you can only respond with text and it will not set "Content-Type"

      app.get('/',(req,res)=>{
           res.end('<b>hello</b>');
      });

2. res.send() will set "ETag" attribute in the response header

      app.get('/',(req,res)=>{
            res.send('<b>hello</b>');
      });

¿Why is this tag important?
The ETag HTTP response header is an identifier for a specific version of a resource. It allows caches to be more efficient, and saves bandwidth, as a web server does not need to send a full response if the content has not changed.

res.end() will NOT set this header attribute

HTML table with fixed headers?

Not-so-clean, but pure HTML/CSS solution.

table {
    overflow-x:scroll;
}

tbody {
    max-height: /*your desired max height*/
    overflow-y:scroll;
    display:block;
}

Updated for IE8+ JSFiddle example

Undefined behavior and sequence points

This is a follow up to my previous answer and contains C++11 related material..

Pre-requisites : An elementary knowledge of Relations (Mathematics).

Is it true that there are no Sequence Points in C++11?

Yes! This is very true.

Sequence Points have been replaced by Sequenced Before and Sequenced After (and Unsequenced and Indeterminately Sequenced) relations in C++11.

What exactly is this 'Sequenced before' thing?

Sequenced Before^(§1.9/13) is a relation which is:

between evaluations executed by a single thread and induces a strict partial order¹

Formally it means given any two evaluations^{(See below)} A and B, if A is sequenced before B, then the execution of A shall precede the execution of B. If A is not sequenced before B and B is not sequenced before A, then A and B are unsequenced ².

Evaluations A and B are indeterminately sequenced when either A is sequenced before B or B is sequenced before A, but it is unspecified which³.

_[NOTES] _{1 : A strict partial order is a binary relation "<" over a set P which is asymmetric, and transitive, i.e., for all a, b, and c in P, we have that:} _{........(i). if a < b then ¬ (b < a) (asymmetry);

........(ii). if a < b and b < c then a < c (transitivity).

2 : The execution of unsequenced evaluations can overlap.

3 : Indeterminately sequenced evaluations cannot overlap, but either could be executed first.}

What is the meaning of the word 'evaluation' in context of C++11?

In C++11, evaluation of an expression (or a sub-expression) in general includes:

value computations (including determining the identity of an object for glvalue evaluation and fetching a value previously assigned to an object for prvalue evaluation) and
initiation of side effects.

Now (§1.9/14) says:

Every value computation and side effect associated with a full-expression is sequenced before every value computation and side effect associated with the next full-expression to be evaluated.

Trivial example:

int x; x = 10; ++x;

Value computation and side effect associated with ++x is sequenced after the value computation and side effect of x = 10;

So there must be some relation between Undefined Behaviour and the above-mentioned things, right?

Yes! Right.

In (§1.9/15) it has been mentioned that

Except where noted, evaluations of operands of individual operators and of subexpressions of individual expressions are unsequenced⁴.

For example :

int main()
{
     int num = 19 ;
     num = (num << 3) + (num >> 3);
}

Evaluation of operands of + operator are unsequenced relative to each other.
Evaluation of operands of << and >> operators are unsequenced relative to each other.

_{4: In an expression that is evaluated more than once during the execution
of a program, unsequenced and indeterminately sequenced evaluations of its subexpressions need not be performed consistently in different evaluations.}

(§1.9/15) The value computations of the operands of an operator are sequenced before the value computation of the result of the operator.

That means in x + y the value computation of x and y are sequenced before the value computation of (x + y).

More importantly

(§1.9/15) If a side effect on a scalar object is unsequenced relative to either

(a) another side effect on the same scalar object

or

(b) a value computation using the value of the same scalar object.

the behaviour is undefined.

Examples:

int i = 5, v[10] = { };
void  f(int,  int);

i = i++ * ++i; // Undefined Behaviour
i = ++i + i++; // Undefined Behaviour
i = ++i + ++i; // Undefined Behaviour
i = v[i++]; // Undefined Behaviour
i = v[++i]: // Well-defined Behavior
i = i++ + 1; // Undefined Behaviour
i = ++i + 1; // Well-defined Behaviour
++++i; // Well-defined Behaviour
f(i = -1, i = -1); // Undefined Behaviour (see below)

When calling a function (whether or not the function is inline), every value computation and side effect associated with any argument expression, or with the postfix expression designating the called function, is sequenced before execution of every expression or statement in the body of the called function. [Note: Value computations and side effects associated with different argument expressions are unsequenced. — end note]

Expressions (5), (7) and (8) do not invoke undefined behaviour. Check out the following answers for a more detailed explanation.

Final Note :

If you find any flaw in the post please leave a comment. Power-users (With rep >20000) please do not hesitate to edit the post for correcting typos and other mistakes.

Get Android Phone Model programmatically

On many popular devices the market name of the device is not available. For example, on the Samsung Galaxy S6 the value of Build.MODEL could be "SM-G920F", "SM-G920I", or "SM-G920W8".

I created a small library that gets the market (consumer friendly) name of a device. It gets the correct name for over 10,000 devices and is constantly updated. If you wish to use my library click the link below:

AndroidDeviceNames Library on Github

If you do not want to use the library above, then this is the best solution for getting a consumer friendly device name:

/** Returns the consumer friendly device name */
public static String getDeviceName() {
  String manufacturer = Build.MANUFACTURER;
  String model = Build.MODEL;
  if (model.startsWith(manufacturer)) {
    return capitalize(model);
  }
  return capitalize(manufacturer) + " " + model;
}

private static String capitalize(String str) {
  if (TextUtils.isEmpty(str)) {
    return str;
  }
  char[] arr = str.toCharArray();
  boolean capitalizeNext = true;

  StringBuilder phrase = new StringBuilder();
  for (char c : arr) {
    if (capitalizeNext && Character.isLetter(c)) {
      phrase.append(Character.toUpperCase(c));
      capitalizeNext = false;
      continue;
    } else if (Character.isWhitespace(c)) {
      capitalizeNext = true;
    }
    phrase.append(c);
  }

  return phrase.toString();
}

Example from my Verizon HTC One M8:

// using method from above
System.out.println(getDeviceName());
// Using https://github.com/jaredrummler/AndroidDeviceNames
System.out.println(DeviceName.getDeviceName());

Result:

HTC6525LVW

HTC One (M8)

How to use Jackson to deserialise an array of objects

you could also create a class which extends ArrayList:

public static class MyList extends ArrayList<Myclass> {}

and then use it like:

List<MyClass> list = objectMapper.readValue(json, MyList.class);

Git: How to commit a manually deleted file?

The answer's here, I think.

It's better if you do git rm <fileName>, though.

How to make CSS width to fill parent?

EDIT:

Those three different elements all have different rendering rules.

So for:

table#bar you need to set the width to 100% otherwise it will be only be as wide as it determines it needs to be. However, if the table rows total width is greater than the width of bar it will expand to its needed width. IF i recall you can counteract this by setting display: block !important; though its been awhile since ive had to fix that. (im sure someone will correct me if im wrong).

textarea#bar i beleive is a block level element so it will follow the rules the same as the div. The only caveat here is that textarea take an attributes of cols and rows which are measured in character columns. If this is specified on the element it will override the width specified by the css.

input#bar is an inline element, so by default you cant assign it width. However the similar to textarea's cols attribute, it has a size attribute on the element that can determine width. That said, you can always specifiy a width by using display: block; in your css for it. Then it will follow the same rendering rules as the div.

td#foo will be rendered as a table-cell which has some craziness to it. Bottom line here is that for your purposes its going to act just like div#foo as far as restricting the width of its contents. The only issue here is going to be potential unwrappable text in the column somewhere which would make it ignore your width setting. Also all cells in the column are going to get the width of the widest cell.

Thats the default behavior of block level element - ie. if width is auto (the default) then it will be 100% of the inner width of the containing element. so in essence:

#foo {width: 800px;}
#bar {padding-left: 2px; padding-right: 2px; margin-left: 2px; margin-right: 2px;}

will give you exactly what you want.

Mouseover or hover vue.js

There's no need for a method here.

HTML

<div v-if="active">
    <h2>Hello World!</h2>
 </div>

 <div v-on:mouseover="active = !active">
    <h1>Hover me!</h1>
 </div>

new Vue({
  el: 'body',
  data: {
    active: false
  }
})

jQuery: Get selected element tag name

This is yet another way:

$('selector')[0].tagName

'POCO' definition

In Java land typically "PO" means "plain old". The rest can be tricky, so I'm guessing that your example (in the context of Java) is "plain old class object".

some other examples

POJO (plain old java object)
POJI (plain old java interface)

jQuery AJAX form using mail() PHP script sends email, but POST data from HTML form is undefined

You are using the wrong parameters name, try:

if($_POST){
    $name = $_POST['name'];
    $email = $_POST['email'];
    $message = $_POST['text'];

//send email
    mail("[email protected]", "51 Deep comment from" .$email, $message);
}

Auto-refreshing div with jQuery - setTimeout or another method?

There's a jQuery Timer plugin you may want to try

Get Value of Radio button group

Your quotes only need to surround the value part of the attribute-equals selector, [attr='val'], like this:

$('a#check_var').click(function() {
  alert($("input:radio[name='r']:checked").val()+ ' '+
        $("input:radio[name='s']:checked").val());
});?

You can see the working version here.

How to set environment variables in Jenkins?

Try Environment Script Plugin (GitHub) which is very similar to EnvInject. It allows you to run a script before the build (after SCM checkout) that generates environment variables for it. E.g.

and in your script, you can print e.g. FOO=bar to the standard output to set that variable.

Example to append to an existing PATH-style variable:

echo PATH+unique_identifier=/usr/local/bin

So you're free to do whatever you need in the script - either cat a file, or run a script in some other language from your project's source tree, etc.

How to print variables in Perl

You should always include all relevant code when asking a question. In this case, the print statement that is the center of your question. The print statement is probably the most crucial piece of information. The second most crucial piece of information is the error, which you also did not include. Next time, include both of those.

print $ids should be a fairly hard statement to mess up, but it is possible. Possible reasons:

$ids is undefined. Gives the warning undefined value in print
$ids is out of scope. With use strict, gives fatal warning Global variable $ids needs explicit package name, and otherwise the undefined warning from above.
You forgot a semi-colon at the end of the line.
You tried to do print $ids $nIds, in which case perl thinks that $ids is supposed to be a filehandle, and you get an error such as print to unopened filehandle.

Explanations

1: Should not happen. It might happen if you do something like this (assuming you are not using strict):

my $var;
while (<>) {
    $Var .= $_;
}
print $var;

Gives the warning for undefined value, because $Var and $var are two different variables.

2: Might happen, if you do something like this:

if ($something) {
    my $var = "something happened!";
}
print $var;

my declares the variable inside the current block. Outside the block, it is out of scope.

3: Simple enough, common mistake, easily fixed. Easier to spot with use warnings.

4: Also a common mistake. There are a number of ways to correctly print two variables in the same print statement:

print "$var1 $var2";  # concatenation inside a double quoted string
print $var1 . $var2;  # concatenation
print $var1, $var2;   # supplying print with a list of args

Lastly, some perl magic tips for you:

use strict;
use warnings;

# open with explicit direction '<', check the return value
# to make sure open succeeded. Using a lexical filehandle.
open my $fh, '<', 'file.txt' or die $!;

# read the whole file into an array and
# chomp all the lines at once
chomp(my @file = <$fh>);
close $fh;

my $ids  = join(' ', @file);
my $nIds = scalar @file;
print "Number of lines: $nIds\n";
print "Text:\n$ids\n";

Reading the whole file into an array is suitable for small files only, otherwise it uses a lot of memory. Usually, line-by-line is preferred.

Variations:

print "@file" is equivalent to $ids = join(' ',@file); print $ids;
$#file will return the last index in @file. Since arrays usually start at 0, $#file + 1 is equivalent to scalar @file.

You can also do:

my $ids;
do {
    local $/;
    $ids = <$fh>;
}

By temporarily "turning off" $/, the input record separator, i.e. newline, you will make <$fh> return the entire file. What <$fh> really does is read until it finds $/, then return that string. Note that this will preserve the newlines in $ids.

Line-by-line solution:

open my $fh, '<', 'file.txt' or die $!; # btw, $! contains the most recent error
my $ids;
while (<$fh>) {
    chomp;
    $ids .= "$_ "; # concatenate with string
}
my $nIds = $.; # $. is Current line number for the last filehandle accessed.

Use of min and max functions in C++

You're missing the entire point of fmin and fmax. It was included in C99 so that modern CPUs could use their native (read SSE) instructions for floating point min and max and avoid a test and branch (and thus a possibly mis-predicted branch). I've re-written code that used std::min and std::max to use SSE intrinsics for min and max in inner loops instead and the speed-up was significant.

How to decorate a class?

No one has explained that you can dynamically define classes. So you can have a decorator that defines (and returns) a subclass:

def addId(cls):

    class AddId(cls):

        def __init__(self, id, *args, **kargs):
            super(AddId, self).__init__(*args, **kargs)
            self.__id = id

        def getId(self):
            return self.__id

    return AddId

Which can be used in Python 2 (the comment from Blckknght which explains why you should continue to do this in 2.6+) like this:

class Foo:
    pass

FooId = addId(Foo)

And in Python 3 like this (but be careful to use super() in your classes):

@addId
class Foo:
    pass

So you can have your cake and eat it - inheritance and decorators!

forward declaration of a struct in C?

Try this

#include <stdio.h>

struct context;

struct funcptrs{
  void (*func0)(struct context *ctx);
  void (*func1)(void);
};

struct context{
    struct funcptrs fps;
}; 

void func1 (void) { printf( "1\n" ); }
void func0 (struct context *ctx) { printf( "0\n" ); }

void getContext(struct context *con){
    con->fps.func0 = func0;  
    con->fps.func1 = func1;  
}

int main(int argc, char *argv[]){
 struct context c;
   c.fps.func0 = func0;
   c.fps.func1 = func1;
   getContext(&c);
   c.fps.func0(&c);
   getchar();
   return 0;
}

How to push both key and value into an Array in Jquery

This code

var title = news.title;
var link = news.link;
arr.push({title : link});

is not doing what you think it does. What gets pushed is a new object with a single member named "title" and with link as the value ... the actual title value is not used. To save an object with two fields you have to do something like

arr.push({title:title, link:link});

or with recent Javascript advances you can use the shortcut

arr.push({title, link}); // Note: comma "," and not colon ":"

If instead you want the key of the object to be the content of the variable title you can use

arr.push({[title]: link}); // Note that title has been wrapped in brackets

How to convert a Collection to List?

Use streams:

someCollection.stream().collect(Collectors.toList())

Xcode 12, building for iOS Simulator, but linking in object file built for iOS, for architecture arm64

After upgrading to Xcode 12 I was still able to build for a real device, but not the simulator. The Podfile build was working only for the real device.

I deleted VALID_ARCHS under Build Settings > User-Defined and it worked! Bashing my head for some time before finding this.

Javascript Append Child AFTER Element

You can use:

if (parentGuest.nextSibling) {
  parentGuest.parentNode.insertBefore(childGuest, parentGuest.nextSibling);
}
else {
  parentGuest.parentNode.appendChild(childGuest);
}

But as Pavel pointed out, the referenceElement can be null/undefined, and if so, insertBefore behaves just like appendChild. So the following is equivalent to the above:

parentGuest.parentNode.insertBefore(childGuest, parentGuest.nextSibling);

Query an object array using linq

Add:

using System.Linq;

to the top of your file.

And then:

Car[] carList = ...
var carMake = 
    from item in carList
    where item.Model == "bmw" 
    select item.Make;

or if you prefer the fluent syntax:

var carMake = carList
    .Where(item => item.Model == "bmw")
    .Select(item => item.Make);

Things to pay attention to:

The usage of item.Make in the select clause instead if s.Make as in your code.
You have a whitespace between item and .Model in your where clause

How to set a timer in android

As I have seen it, java.util.Timer is the most used for implementing a timer.

For a repeating task:

new Timer().scheduleAtFixedRate(task, after, interval);

For a single run of a task:

new Timer().schedule(task, after);

task being the method to be executed
after the time to initial execution
(interval the time for repeating the execution)

Test for non-zero length string in Bash: [ -n "$var" ] or [ "$var" ]

It is better to use the more powerful [[ as far as Bash is concerned.

Usual cases

if [[ $var ]]; then   # var is set and it is not empty
if [[ ! $var ]]; then # var is not set or it is set to an empty string

The above two constructs look clean and readable. They should suffice in most cases.

Note that we don't need to quote the variable expansions inside [[ as there is no danger of word splitting and globbing.

To prevent shellcheck's soft complaints about [[ $var ]] and [[ ! $var ]], we could use the -n option.

Rare cases

In the rare case of us having to make a distinction between "being set to an empty string" vs "not being set at all", we could use these:

if [[ ${var+x} ]]; then           # var is set but it could be empty
if [[ ! ${var+x} ]]; then         # var is not set
if [[ ${var+x} && ! $var ]]; then # var is set and is empty

We can also use the -v test:

if [[ -v var ]]; then             # var is set but it could be empty
if [[ ! -v var ]]; then           # var is not set
if [[ -v var && ! $var ]]; then   # var is set and is empty
if [[ -v var && -z $var ]]; then  # var is set and is empty

Related posts and documentation

There are a plenty of posts related to this topic. Here are a few:

SELECT * FROM in MySQLi

you can use get_result() on the statement.

http://php.net/manual/en/mysqli-stmt.get-result.php

How to list all properties of a PowerShell object

The most succinct way to do this is:

Get-WmiObject -Class win32_computersystem -Property *

Running multiple commands with xargs

One thing I do is to add to .bashrc/.profile this function:

function each() {
    while read line; do
        for f in "$@"; do
            $f $line
        done
    done
}

then you can do things like

... | each command1 command2 "command3 has spaces"

which is less verbose than xargs or -exec. You could also modify the function to insert the value from the read at an arbitrary location in the commands to each, if you needed that behavior also.

How can I have linebreaks in my long LaTeX equations?

multline is best to use. Instead, you can use dmath, split as well.

Here is an example:

\begin{multline}
  {\text {\bf \emph {T(u)}}} ={  \alpha *}{\frac{\sum_{i=1}^{\text{\bf \emph {I(u)}}}{{\text{\bf \emph {S(u,i)}}}* {\text {\bf \emph {Cr(P(u,i))}}} * {\text {\bf \emph {TF(u,i)}}}}}{\text {\bf \emph {I(u)}}}}  \\
   +{  \beta *}{\frac{\sum_{i=1}^{\text{\bf \emph {$I_h$(u)}}}{{\text{\bf \emph {S(u,i)}}}* {\text {\bf \emph {Cr(P(u,i))}}} * {\text {\bf \emph {TF(u,i)}}}}}{\text {\bf \emph {$I_h$(u)}}}}
\end{multline}

Rownum in postgresql

If you have a unique key, you may use COUNT(*) OVER ( ORDER BY unique_key ) as ROWNUM

SELECT t.*, count(*) OVER (ORDER BY k ) ROWNUM 
FROM yourtable t;

| k |     n | rownum |
|---|-------|--------|
| a | TEST1 |      1 |
| b | TEST2 |      2 |
| c | TEST2 |      3 |
| d | TEST4 |      4 |

DEMO

Jquery: how to trigger click event on pressing enter key

Try This

$('#twitterSearch').keydown(function(event){ 
    var keyCode = (event.keyCode ? event.keyCode : event.which);   
    if (keyCode == 13) {
        $('#startSearch').trigger('click');
    }
});

Hope it helps you

How to use `replace` of directive definition?

You are getting confused with transclude: true, which would append the inner content.

replace: true means that the content of the directive template will replace the element that the directive is declared on, in this case the <div myd1> tag.

http://plnkr.co/edit/k9qSx15fhSZRMwgAIMP4?p=preview

For example without replace:true

<div myd1><span class="replaced" myd1="">directive template1</span></div>

and with replace:true

<span class="replaced" myd1="">directive template1</span>

As you can see in the latter example, the div tag is indeed replaced.

Single huge .css file vs. multiple smaller specific .css files?

There is a tipping point at which it's beneficial to have more than one css file.

A site with 1M+ pages, which the average user is likely to only ever see say 5 of, might have a stylesheet of immense proportions, so trying to save the overhead of a single additional request per page load by having a massive initial download is false economy.

Stretch the argument to the extreme limit - it's like suggesting that there should be one large stylesheet maintained for the entire web. Clearly nonsensical.

The tipping point will be different for each site though so there's no hard and fast rule. It will depend upon the quantity of unique css per page, the number of pages, and the number of pages the average user is likely to routinely encounter while using the site.

High-precision clock in Python

Python 3.7 introduces 6 new time functions with nanosecond resolution, for example instead of time.time() you can use time.time_ns() to avoid floating point imprecision issues:

import time
print(time.time())
# 1522915698.3436284
print(time.time_ns())
# 1522915698343660458

These 6 functions are described in PEP 564:

time.clock_gettime_ns(clock_id)

time.clock_settime_ns(clock_id, time:int)

time.monotonic_ns()

time.perf_counter_ns()

time.process_time_ns()

time.time_ns()

These functions are similar to the version without the _ns suffix, but return a number of nanoseconds as a Python int.

How to make a progress bar

You can do it by controlling the width of a div via css. Something roughly along these lines:

<div id="container" style="width:100%; height:50px; border:1px solid black;">
  <div id="progress-bar" style="width:50%;/*change this width */
       background-image:url(someImage.png);
       height:45px;">
  </div>
</div>

That width value can be sent in from php if you so desire.

How to detect when a youtube video finishes playing?

This can be done through the youtube player API:

http://jsfiddle.net/7Gznb/

Working example:

    <div id="player"></div>

    <script src="http://www.youtube.com/player_api"></script>

    <script>

        // create youtube player
        var player;
        function onYouTubePlayerAPIReady() {
            player = new YT.Player('player', {
              width: '640',
              height: '390',
              videoId: '0Bmhjf0rKe8',
              events: {
                onReady: onPlayerReady,
                onStateChange: onPlayerStateChange
              }
            });
        }

        // autoplay video
        function onPlayerReady(event) {
            event.target.playVideo();
        }

        // when video ends
        function onPlayerStateChange(event) {        
            if(event.data === 0) {          
                alert('done');
            }
        }

    </script>

How to print the current time in a Batch-File?

we can easily print the current time and date using echo and system variables as below.

echo %DATE% %TIME%

output example: 13-Sep-19 15:53:05.62

diff current working copy of a file with another branch's committed copy

You're trying to compare your working tree with a particular branch name, so you want this:

git diff master -- foo

Which is from this form of git-diff (see the git-diff manpage)

   git diff [--options] <commit> [--] [<path>...]
       This form is to view the changes you have in your working tree
       relative to the named <commit>. You can use HEAD to compare it with
       the latest commit, or a branch name to compare with the tip of a
       different branch.

FYI, there is also a --cached (aka --staged) option for viewing the diff of what you've staged, rather than everything in your working tree:

   git diff [--options] --cached [<commit>] [--] [<path>...]
       This form is to view the changes you staged for the next commit
       relative to the named <commit>.
       ...
       --staged is a synonym of --cached.

How do you run a crontab in Cygwin on Windows?

hat tip http://linux.subogero.com/894/cron-on-cygwin/

Start the cygwin-setup and add the “cron” package from the “Admin” category.

We’ll run cron as a service by user SYSTEM. Poor SYSTEM therefore needs a home directory and a shell. The “/etc/passwd” file will define them.

$ mkdir /root
$ chown SYSTEM:root /root
$ mcedit /etc/passwd
SYSTEM:*:......:/root:/bin/bash

The start the service:

$ cron-config
Do you want to remove or reinstall it (yes/no) yes
Do you want to install the cron daemon as a service? (yes/no) yes
Enter the value of CYGWIN for the daemon: [ ] ntsec
Do you want the cron daemon to run as yourself? (yes/no) no
Do you want to start the cron daemon as a service now? (yes/no) yes

Local users can now define their scheduled tasks like this (crontab will start your favourite editor):

$ crontab -e  # edit your user specific cron-table HOME=/home/foo
PATH=/usr/local/bin:/usr/bin:/bin:$PATH
# testing - one per line
* * * * *   touch ~/cron
@reboot     ~/foo.sh
45 11 * * * ~/lunch_message_to_mates.sh

Domain users: it does not work. Poor cron is unable to run scheduled tasks on behalf of domain users on the machine. But there is another way: cron also runs stuff found in the system level cron table in “/etc/crontab”. So insert your suff there, so that SYSTEM does it on its own behalf:

$ touch /etc/crontab
$ chown SYSTEM /etc/crontab
$ mcedit /etc/crontab
HOME=/root
PATH=/usr/local/bin:/usr/bin:/bin:$PATH
* * * * *   SYSTEM touch ~/cron
@reboot     SYSTEM rm -f /tmp/.ssh*

Finally a few words about crontab entries. They are either environment settings or scheduled commands. As seen above, on Cygwin it’s best to create a usable PATH. Home dir and shell are normally taken from “/etc/passwd”.

As to the columns of scheduled commands see the manual page.

If certain crontab entries do not run, the best diagnostic tool is this:

$ cronevents

How to fix C++ error: expected unqualified-id

As a side note, consider passing strings in setWord() as const references to avoid excess copying. Also, in displayWord, consider making this a const function to follow const-correctness.

void setWord(const std::string& word) {
  theWord = word;
}

How to select rows for a specific date, ignoring time in SQL Server

select * from sales where salesDate between '11/11/2010' and '12/11/2010' --if using dd/mm/yyyy

The more correct way to do it:

DECLARE @myDate datetime
SET @myDate = '11/11/2010'
select * from sales where salesDate>=@myDate and salesDate<dateadd(dd,1,@myDate)

If only the date is specified, it means total midnight. If you want to make sure intervals don't overlap, switch the between with a pair of >= and <

you can do it within one single statement, but it's just that the value is used twice.

Thin Black Border for a Table

Style the td and th instead

td, th {
    border: 1px solid black;
}

And also to make it so there is no spacing between cells use:

table {
    border-collapse: collapse;
}

(also note, you have border-style: none; which should be border-style: solid;)

See an example here: http://jsfiddle.net/KbjNr/

How to change value for innodb_buffer_pool_size in MySQL on Mac OS?

For standard OS X installations of MySQL you will find my.cnf located in the /etc/ folder.

Steps to update this variable:

Load Terminal.
Type cd /etc/.
sudo vi my.cnf.
This file should already exist (if not please use sudo find / -name 'my.cnf' 2>1 - this will hide the errors and only report the successfile file location).
Using vi(m) find the line innodb_buffer_pool_size, press i to start making changes.
When finished, press esc, shift+colon and type wq.
Profit (done).

How do you connect localhost in the Android emulator?

Use 10.0.2.2 for default AVD and 10.0.3.2 for Genymotion

How do I make a https post in Node Js without any third party module?

For example, like this:

const querystring = require('querystring');
const https = require('https');

var postData = querystring.stringify({
    'msg' : 'Hello World!'
});

var options = {
  hostname: 'posttestserver.com',
  port: 443,
  path: '/post.php',
  method: 'POST',
  headers: {
       'Content-Type': 'application/x-www-form-urlencoded',
       'Content-Length': postData.length
     }
};

var req = https.request(options, (res) => {
  console.log('statusCode:', res.statusCode);
  console.log('headers:', res.headers);

  res.on('data', (d) => {
    process.stdout.write(d);
  });
});

req.on('error', (e) => {
  console.error(e);
});

req.write(postData);
req.end();

Error reading JObject from JsonReader. Current JsonReader item is not an object: StartArray. Path

In this case that you know that you have all items in the first place on array you can parse the string to JArray and then parse the first item using JObject.Parse

var  jsonArrayString = @"
[
  {
    ""country"": ""India"",
    ""city"": ""Mall Road, Gurgaon"",
  },
  {
    ""country"": ""India"",
    ""city"": ""Mall Road, Kanpur"",
  }
]";
JArray jsonArray = JArray.Parse(jsonArrayString);
dynamic data = JObject.Parse(jsonArray[0].ToString());

Jest spyOn function called

You were almost done without any changes besides how you spyOn. When you use the spy, you have two options: spyOn the App.prototype, or component component.instance().

const spy = jest.spyOn(Class.prototype, "method")

The order of attaching the spy on the class prototype and rendering (shallow rendering) your instance is important.

const spy = jest.spyOn(App.prototype, "myClickFn");
const instance = shallow(<App />);

The App.prototype bit on the first line there are what you needed to make things work. A JavaScript class doesn't have any of its methods until you instantiate it with new MyClass(), or you dip into the MyClass.prototype. For your particular question, you just needed to spy on the App.prototype method myClickFn.

jest.spyOn(component.instance(), "method")

const component = shallow(<App />);
const spy = jest.spyOn(component.instance(), "myClickFn");

This method requires a shallow/render/mount instance of a React.Component to be available. Essentially spyOn is just looking for something to hijack and shove into a jest.fn(). It could be:

A plain object:

const obj = {a: x => (true)};
const spy = jest.spyOn(obj, "a");

A class:

class Foo {
    bar() {}
}

const nope = jest.spyOn(Foo, "bar");
// THROWS ERROR. Foo has no "bar" method.
// Only an instance of Foo has "bar".
const fooSpy = jest.spyOn(Foo.prototype, "bar");
// Any call to "bar" will trigger this spy; prototype or instance

const fooInstance = new Foo();
const fooInstanceSpy = jest.spyOn(fooInstance, "bar");
// Any call fooInstance makes to "bar" will trigger this spy.

Or a React.Component instance:

const component = shallow(<App />);
/*
component.instance()
-> {myClickFn: f(), render: f(), ...etc}
*/
const spy = jest.spyOn(component.instance(), "myClickFn");

Or a React.Component.prototype:

/*
App.prototype
-> {myClickFn: f(), render: f(), ...etc}
*/
const spy = jest.spyOn(App.prototype, "myClickFn");
// Any call to "myClickFn" from any instance of App will trigger this spy.

I've used and seen both methods. When I have a beforeEach() or beforeAll() block, I might go with the first approach. If I just need a quick spy, I'll use the second. Just mind the order of attaching the spy.

EDIT: If you want to check the side effects of your myClickFn you can just invoke it in a separate test.

const app = shallow(<App />);
app.instance().myClickFn()
/*
Now assert your function does what it is supposed to do...
eg.
expect(app.state("foo")).toEqual("bar");
*/

EDIT: Here is an example of using a functional component. Keep in mind that any methods scoped within your functional component are not available for spying. You would be spying on function props passed into your functional component and testing the invocation of those. This example explores the use of jest.fn() as opposed to jest.spyOn, both of which share the mock function API. While it does not answer the original question, it still provides insight on other techniques that could suit cases indirectly related to the question.

function Component({ myClickFn, items }) {
   const handleClick = (id) => {
       return () => myClickFn(id);
   };
   return (<>
       {items.map(({id, name}) => (
           <div key={id} onClick={handleClick(id)}>{name}</div>
       ))}
   </>);
}

const props = { myClickFn: jest.fn(), items: [/*...{id, name}*/] };
const component = render(<Component {...props} />);
// Do stuff to fire a click event
expect(props.myClickFn).toHaveBeenCalledWith(/*whatever*/);

Freely convert between List<T> and IEnumerable<T>

A List<T> is an IEnumerable<T>, so actually, there's no need to 'convert' a List<T> to an IEnumerable<T>. Since a List<T> is an IEnumerable<T>, you can simply assign a List<T> to a variable of type IEnumerable<T>.

The other way around, not every IEnumerable<T> is a List<T> offcourse, so then you'll have to call the ToList() member method of the IEnumerable<T>.

When should you use 'friend' in C++?

Friend comes handy when you are building a container and you want to implement an iterator for that class.

Mockito How to mock and assert a thrown exception?

Use Mockito's doThrow and then catch the desired exception to assert it was thrown later.

@Test
public void fooShouldThrowMyException() {
    // given
    val myClass = new MyClass();
    val arg = mock(MyArgument.class);
    doThrow(MyException.class).when(arg).argMethod(any());
    Exception exception = null;

    // when
    try {
        myClass.foo(arg);
    } catch (MyException t) {
        exception = t;
    }

    // then
    assertNotNull(exception);
}

Github Windows 'Failed to sync this branch'

I had this problem and found it was to do with the proxy. I fixed the problem using this command:

 git config --global http.proxy %HTTP_PROXY%

Fixed page header overlaps in-page anchors

It feels somewhat hacky to my purist mind but as a css-only solution you can add padding to the active anchored element using the :target selector:

_x000D_

html, body {height:100%; min-height:100%; margin:0;}_x000D_
body {min-height:200%;}_x000D_
header {display:inline-block; position:fixed; font-size:1.5em; height:100px; top:0; left:0; right:0; line-height:100px; background:black; text-align:center;}_x000D_
header a {color:#fff;}_x000D_
section {padding:30px; margin:20px;}_x000D_
section:first-of-type, section:target {padding-top:130px;}

_x000D_

<header><a href="#one">#One</a> <a href="#two">#two</a> <a href="#three">#three</a></header>_x000D_
<section id="one"><h1>One</h1>Aenean lacinia bibendum nulla sed consectetur. Nullam id dolor id nibh ultricies vehicula ut id elit. Integer posuere erat a ante venenatis dapibus posuere velit aliquet.</section>_x000D_
<section id="two"><h1>Two</h1>Aenean lacinia bibendum nulla sed consectetur. Nullam id dolor id nibh ultricies vehicula ut id elit. Integer posuere erat a ante venenatis dapibus posuere velit aliquet.</section>_x000D_
<section id="three"><h1>Three</h1>Aenean lacinia bibendum nulla sed consectetur. Nullam id dolor id nibh ultricies vehicula ut id elit. Integer posuere erat a ante venenatis dapibus posuere velit aliquet.</section>

_x000D_

Angularjs: Get element in controller

Create custom directive

masterApp.directive('ngRenderCallback', function() {
    return {
        restrict: "A",
        link: function ($scope, element, attrs) {
            setTimeout(function(){ 
                $scope[attrs.ngEl] = element[0];
                $scope.$eval(attrs.ngRenderCallback);               
            }, 30);
        }
    }
});

code for html template

<div ng-render-callback="fnRenderCarousel('carouselA')" ng-el="carouselA"></div>

function in controller

$scope.fnRenderCarousel = function(elName){
    $($scope[elName]).carousel();
}

A simple algorithm for polygon intersection

You have not given us your representation of a polygon. So I am choosing (more like suggesting) one for you :)

Represent each polygon as one big convex polygon, and a list of smaller convex polygons which need to be 'subtracted' from that big convex polygon.

Now given two polygons in that representation, you can compute the intersection as:

Compute intersection of the big convex polygons to form the big polygon of the intersection. Then 'subtract' the intersections of all the smaller ones of both to get a list of subracted polygons.

You get a new polygon following the same representation.

Since convex polygon intersection is easy, this intersection finding should be easy too.

This seems like it should work, but I haven't given it more deeper thought as regards to correctness/time/space complexity.

What is the difference between init and call?

__init__ is a special method in Python classes, it is the constructor method for a class. It is called whenever an object of the class is constructed or we can say it initialises a new object. Example:

    In [4]: class A:
   ...:     def __init__(self, a):
   ...:         print(a)
   ...:
   ...: a = A(10) # An argument is necessary
10

If we use A(), it will give an error TypeError: __init__() missing 1 required positional argument: 'a' as it requires 1 argument a because of __init__ .

........

__call__ when implemented in the Class helps us invoke the Class instance as a function call.

Example:

In [6]: class B:
   ...:     def __call__(self,b):
   ...:         print(b)
   ...:
   ...: b = B() # Note we didn't pass any arguments here
   ...: b(20)   # Argument passed when the object is called
   ...:
20

Here if we use B(), it runs just fine because it doesn't have an __init__ function here.

How do I get the last inserted ID of a MySQL table in PHP?

Use mysqli as mysql is depricating

<?php
$mysqli = new mysqli("localhost", "yourUsername", "yourPassword", "yourDB");

/* check connection */
if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}
// Conside employee table with id,name,designation
$query = "INSERT INTO myCity VALUES (NULL, 'Ram', 'Developer')";
$mysqli->query($query);

printf ("New Record has id %d.\n", $mysqli->insert_id);

/* close connection */
$mysqli->close();
?>

need to test if sql query was successful

This is the simplest way you could test

$query = $DB->query("UPDATE exp_members SET group_id = '$group_id' WHERE member_id = '$member_id'");

if($query) // will return true if succefull else it will return false
{
// code here
}

How to align footer (div) to the bottom of the page?

I am a newbie and these methods are not working for me. However, I tried a margin-top property in css and simply added the value of content pixels +5.

Example: my content layout had a height of 1000px so I put a margin-top value of 1005px in the footer css which gave me a 5px border and a footer that sits delightfully at the bottom of my site.

Probably an amateur way of doing it, but EFFECTIVE!!!

How to set selected value of jquery select2?

Also as I tried, when use ajax in select2, the programmatic control methods for set new values in select2 does not work for me! Now I write these code for resolve the problem:

$('#sel')
    .empty() //empty select
    .append($("<option/>") //add option tag in select
        .val("20") //set value for option to post it
        .text("nabi")) //set a text for show in select
    .val("20") //select option of select2
    .trigger("change"); //apply to select2

You can test complete sample code in here link: https://jsfiddle.net/NabiKAZ/2g1qq26v/32/
In this sample code there is a ajax select2 and you can set new value with a button.

_x000D_

$("#btn").click(function() {_x000D_
  $('#sel')_x000D_
    .empty() //empty select_x000D_
    .append($("<option/>") //add option tag in select_x000D_
      .val("20") //set value for option to post it_x000D_
      .text("nabi")) //set a text for show in select_x000D_
    .val("20") //select option of select2_x000D_
    .trigger("change"); //apply to select2_x000D_
});_x000D_
_x000D_
$("#sel").select2({_x000D_
  ajax: {_x000D_
    url: "https://api.github.com/search/repositories",_x000D_
    dataType: 'json',_x000D_
    delay: 250,_x000D_
    data: function(params) {_x000D_
      return {_x000D_
        q: params.term, // search term_x000D_
        page: params.page_x000D_
      };_x000D_
    },_x000D_
    processResults: function(data, params) {_x000D_
      // parse the results into the format expected by Select2_x000D_
      // since we are using custom formatting functions we do not need to_x000D_
      // alter the remote JSON data, except to indicate that infinite_x000D_
      // scrolling can be used_x000D_
      params.page = params.page || 1;_x000D_
_x000D_
      return {_x000D_
        results: data.items,_x000D_
        pagination: {_x000D_
          more: (params.page * 30) < data.total_count_x000D_
        }_x000D_
      };_x000D_
    },_x000D_
    cache: true_x000D_
  },_x000D_
  escapeMarkup: function(markup) {_x000D_
    return markup;_x000D_
  }, // let our custom formatter work_x000D_
  minimumInputLength: 1,_x000D_
  templateResult: formatRepo, // omitted for brevity, see the source of this page_x000D_
  templateSelection: formatRepoSelection // omitted for brevity, see the source of this page_x000D_
});_x000D_
_x000D_
function formatRepo(repo) {_x000D_
  if (repo.loading) return repo.text;_x000D_
_x000D_
  var markup = "<div class='select2-result-repository clearfix'>" +_x000D_
    "<div class='select2-result-repository__avatar'><img src='" + repo.owner.avatar_url + "' /></div>" +_x000D_
    "<div class='select2-result-repository__meta'>" +_x000D_
    "<div class='select2-result-repository__title'>" + repo.full_name + "</div>";_x000D_
_x000D_
  if (repo.description) {_x000D_
    markup += "<div class='select2-result-repository__description'>" + repo.description + "</div>";_x000D_
  }_x000D_
_x000D_
  markup += "<div class='select2-result-repository__statistics'>" +_x000D_
    "<div class='select2-result-repository__forks'><i class='fa fa-flash'></i> " + repo.forks_count + " Forks</div>" +_x000D_
    "<div class='select2-result-repository__stargazers'><i class='fa fa-star'></i> " + repo.stargazers_count + " Stars</div>" +_x000D_
    "<div class='select2-result-repository__watchers'><i class='fa fa-eye'></i> " + repo.watchers_count + " Watchers</div>" +_x000D_
    "</div>" +_x000D_
    "</div></div>";_x000D_
_x000D_
  return markup;_x000D_
}_x000D_
_x000D_
function formatRepoSelection(repo) {_x000D_
  return repo.full_name || repo.text;_x000D_
}

_x000D_

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script>_x000D_
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.2-rc.1/css/select2.min.css">_x000D_
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.2-rc.1/js/select2.min.js"></script>_x000D_
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css">_x000D_
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
<link rel="stylesheet" type="text/css" href="https://select2.org/assets/a7be624d756ba99faa354e455aed250d.css">_x000D_
_x000D_
<select id="sel" multiple="multiple" class="col-xs-5">_x000D_
</select>_x000D_
_x000D_
<button id="btn">Set Default</button>

_x000D_

How can I sort a std::map first by value, then by key?

As explained in Nawaz's answer, you cannot sort your map by itself as you need it, because std::map sorts its elements based on the keys only. So, you need a different container, but if you have to stick to your map, then you can still copy its content (temporarily) into another data structure.

I think, the best solution is to use a std::set storing flipped key-value pairs as presented in ks1322's answer. The std::set is sorted by default and the order of the pairs is exactly as you need it:

3) If lhs.first<rhs.first, returns true. Otherwise, if rhs.first<lhs.first, returns false. Otherwise, if lhs.second<rhs.second, returns true. Otherwise, returns false.

This way you don't need an additional sorting step and the resulting code is quite short:

std::map<std::string, int> m;  // Your original map.
m["realistically"] = 1;
m["really"]        = 8;
m["reason"]        = 4;
m["reasonable"]    = 3;
m["reasonably"]    = 1;
m["reassemble"]    = 1;
m["reassembled"]   = 1;
m["recognize"]     = 2;
m["record"]        = 92;
m["records"]       = 48;
m["recs"]          = 7;

std::set<std::pair<int, std::string>> s;  // The new (temporary) container.

for (auto const &kv : m)
    s.emplace(kv.second, kv.first);  // Flip the pairs.

for (auto const &vk : s)
    std::cout << std::setw(3) << vk.first << std::setw(15) << vk.second << std::endl;

Output:

  1  realistically
  1     reasonably
  1     reassemble
  1    reassembled
  2      recognize
  3     reasonable
  4         reason
  7           recs
  8         really
 48        records
 92         record

Code on Ideone

Note: Since C++17 you can use range-based for loops together with structured bindings for iterating over a map. As a result, the code for copying your map becomes even shorter and more readable:

for (auto const &[k, v] : m)
    s.emplace(v, k);  // Flip the pairs.

find difference between two text files with one item per line

I successfully used

diff "${file1}" "${file2}" | grep "<" | sed 's/^<//g' > "${diff_file}"

Outputting the difference to a file.

Fill background color left to right CSS

A single css code on hover can do the trick: box-shadow: inset 100px 0 0 0 #e0e0e0;

A complete demo can be found in my fiddle:

https://jsfiddle.net/shuvamallick/3o0h5oka/

What is the difference between public, protected, package-private and private in Java?

Following block diagram explain how data members of base class are inherited when derived class access mode is private.

Note: Declaring data members with private access specifier is known as data hiding.

Source : Access Specifiers – Private, Public and Protected

Make an image follow mouse pointer

Here's my code (not optimized but a full working example):

<head>
<style>
#divtoshow {position:absolute;display:none;color:white;background-color:black}
#onme {width:150px;height:80px;background-color:yellow;cursor:pointer}
</style>
<script type="text/javascript">
var divName = 'divtoshow'; // div that is to follow the mouse (must be position:absolute)
var offX = 15;          // X offset from mouse position
var offY = 15;          // Y offset from mouse position

function mouseX(evt) {if (!evt) evt = window.event; if (evt.pageX) return evt.pageX; else if (evt.clientX)return evt.clientX + (document.documentElement.scrollLeft ?  document.documentElement.scrollLeft : document.body.scrollLeft); else return 0;}
function mouseY(evt) {if (!evt) evt = window.event; if (evt.pageY) return evt.pageY; else if (evt.clientY)return evt.clientY + (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop); else return 0;}

function follow(evt) {
    var obj = document.getElementById(divName).style;
    obj.left = (parseInt(mouseX(evt))+offX) + 'px';
    obj.top = (parseInt(mouseY(evt))+offY) + 'px'; 
    }
document.onmousemove = follow;
</script>
</head>
<body>
<div id="divtoshow">test</div>
<br><br>
<div id='onme' onMouseover='document.getElementById(divName).style.display="block"' onMouseout='document.getElementById(divName).style.display="none"'>Mouse over this</div>
</body>

What does a question mark represent in SQL queries?

The ? is to allow Parameterized Query. These parameterized query is to allow type-specific value when replacing the ? with their respective value.

That's all to it.

Here's a reason of why it's better to use Parameterized Query. Basically, it's easier to read and debug.

How to roundup a number to the closest ten?

You can use the function MROUND(<reference cell>, <round to multiple of digit needed>).

Example:

For a value A1 = 21 round to multiple of 10 it would be written as =MROUND(A1,10) for which Result = 20
For a value Z4 = 55.1 round to multiple of 10 it would be written as =MROUND(Z4,10) for which Result = 60

NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder

Copy all order entries of home folder .iml file into your /src/main/main.iml file. This will solve the problem.

iOS Safari – How to disable overscroll but allow scrollable divs to scroll normally?

this one works for me (plain javascript)

var fixScroll = function (className, border) {  // className = class of scrollElement(s), border: borderTop + borderBottom, due to offsetHeight
var reg = new RegExp(className,"i"); var off = +border + 1;
function _testClass(e) { var o = e.target; while (!reg.test(o.className)) if (!o || o==document) return false; else o = o.parentNode; return o;}
document.ontouchmove  = function(e) { var o = _testClass(e); if (o) { e.stopPropagation(); if (o.scrollTop == 0) { o.scrollTop += 1; e.preventDefault();}}}
document.ontouchstart = function(e) { var o = _testClass(e); if (o && o.scrollHeight >= o.scrollTop + o.offsetHeight - off) o.scrollTop -= off;}
}

fixScroll("fixscroll",2); // assuming I have a 1px border in my DIV

html:

<div class="fixscroll" style="border:1px gray solid">content</div>

Find() vs. Where().FirstOrDefault()

Difference between jar and war in Java

JAR files allow to package multiple files in order to use it as a library, plugin, or any kind of application. On the other hand, WAR files are used only for web applications.

JAR can be created with any desired structure. In contrast, WAR has a predefined structure with WEB-INF and META-INF directories.

A JAR file allows Java Runtime Environment (JRE) to deploy an entire application including the classes and the associated resources in a single request. On the other hand, a WAR file allows testing and deploying a web application easily.

How to search by key=>value in a multidimensional array in PHP

And another version that returns the key value from the array element in which the value is found (no recursion, optimized for speed):

// if the array is 
$arr['apples'] = array('id' => 1);
$arr['oranges'] = array('id' => 2);

//then 
print_r(search_array($arr, 'id', 2);
// returns Array ( [oranges] => Array ( [id] => 2 ) ) 
// instead of Array ( [0] => Array ( [id] => 2 ) )

// search array for specific key = value
function search_array($array, $key, $value) {
  $return = array();   
  foreach ($array as $k=>$subarray){  
    if (isset($subarray[$key]) && $subarray[$key] == $value) {
      $return[$k] = $subarray;
      return $return;
    } 
  }
}

Thanks to all who posted here.

Drop a temporary table if it exists

What you asked for is:

IF OBJECT_ID('tempdb..##CLIENTS_KEYWORD') IS NOT NULL
    BEGIN
       DROP TABLE ##CLIENTS_KEYWORD

       CREATE TABLE ##CLIENTS_KEYWORD(client_id int)

    END
ELSE
   CREATE TABLE ##CLIENTS_KEYWORD(client_id int) 

IF OBJECT_ID('tempdb..##TEMP_CLIENTS_KEYWORD') IS NOT NULL
    BEGIN
       DROP TABLE ##TEMP_CLIENTS_KEYWORD

       CREATE TABLE ##TEMP_CLIENTS_KEYWORD(client_id int)

    END
ELSE
   CREATE TABLE ##TEMP_CLIENTS_KEYWORD(client_id int)

Since you're always going to create the table, regardless of whether the table is deleted or not; a slightly optimised solution is:

IF OBJECT_ID('tempdb..##CLIENTS_KEYWORD') IS NOT NULL
   DROP TABLE ##CLIENTS_KEYWORD

CREATE TABLE ##CLIENTS_KEYWORD(client_id int) 

IF OBJECT_ID('tempdb..##TEMP_CLIENTS_KEYWORD') IS NOT NULL
   DROP TABLE ##TEMP_CLIENTS_KEYWORD

CREATE TABLE ##TEMP_CLIENTS_KEYWORD(client_id int)

fetch from origin with deleted remote branches?

If git fetch -p origin does not work for some reason (like because the origin repo no longer exists or you are unable to reach it), another solution is to remove the information which is stored locally on that branch by doing from the root of the repo:

rm .git/refs/remotes/origin/DELETED_BRANCH

or if it is stored in the file .git/packed-refs by deleting the corresponding line which is like

7a9930974b02a3b31cb2ebd17df6667514962685 refs/remotes/origin/DELETED_BRANCH

How do I determine the current operating system with Node.js

const path = require('path');

if (path.sep === "\\") {
console.log("Windows");
} else {
console.log("Not Windows");
}

When to use static methods

There are some valid reasons to use static methods:

Performance: if you want some code to be run, and don't want to instantiate an extra object to do so, shove it into a static method. The JVM also can optimize static methods a lot (I think I've once read James Gosling declaring that you don't need custom instructions in the JVM, since static methods will be just as fast, but couldn't find the source - thus it could be completely false). Yes, it is micro-optimization, and probably unneeded. And we programmers never do unneeded things just because they are cool, right?
Practicality: instead of calling new Util().method(arg), call Util.method(arg), or method(arg) with static imports. Easier, shorter.
Adding methods: you really wanted the class String to have a removeSpecialChars() instance method, but it's not there (and it shouldn't, since your project's special characters may be different from the other project's), and you can't add it (since Java is somewhat sane), so you create an utility class, and call removeSpecialChars(s) instead of s.removeSpecialChars(). Sweet.
Purity: taking some precautions, your static method will be a pure function, that is, the only thing it depends on is its parameters. Data in, data out. This is easier to read and debug, since you don't have inheritance quirks to worry about. You can do it with instance methods too, but the compiler will help you a little more with static methods (by not allowing references to instance attributes, overriding methods, etc.).

You'll also have to create a static method if you want to make a singleton, but... don't. I mean, think twice.

Now, more importantly, why you wouldn't want to create a static method? Basically, polymorphism goes out of the window. You'll not be able to override the method, ~~nor declare it in an interface~~ (pre-Java 8). It takes a lot of flexibility out from your design. Also, if you need state, you'll end up with lots of concurrency bugs and/or bottlenecks if you are not careful.

Where to put default parameter value in C++?

Default parameter values must appear on the declaration, since that is the only thing that the caller sees.

EDIT: As others point out, you can have the argument on the definition, but I would advise writing all code as if that wasn't true.

Recyclerview and handling different type of row inflation

getItemViewType(int position) is the key

In my opinion,the starting point to create this kind of recyclerView is the knowledge of this method. Since this method is optional to override therefore it is not visible in RecylerView class by default which in turn makes many developers(including me) wonder where to begin. Once you know that this method exists, creating such RecyclerView would be a cakewalk.

How to do it ?

You can create a RecyclerView with any number of different Views(ViewHolders). But for better readability lets take an example of RecyclerView with two Viewholders.
Remember these 3 simple steps and you will be good to go.

Override public int getItemViewType(int position)
Return different ViewHolders based on the ViewType in onCreateViewHolder() method

Populate View based on the itemViewType in onBindViewHolder() method

Here is a code snippet for you

public class YourListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private static final int LAYOUT_ONE= 0;
    private static final int LAYOUT_TWO= 1;

    @Override
    public int getItemViewType(int position)
    {
        if(position==0)
           return LAYOUT_ONE;
        else
           return LAYOUT_TWO;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view =null;
        RecyclerView.ViewHolder viewHolder = null;

        if(viewType==LAYOUT_ONE)
        {
           view = LayoutInflater.from(parent.getContext()).inflate(R.layout.one,parent,false);
           viewHolder = new ViewHolderOne(view);
        }
        else
        {
           view = LayoutInflater.from(parent.getContext()).inflate(R.layout.two,parent,false);
           viewHolder= new ViewHolderTwo(view);
        }

        return viewHolder;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {

       if(holder.getItemViewType()== LAYOUT_ONE)
       {
           // Typecast Viewholder 
           // Set Viewholder properties 
           // Add any click listener if any 
       }
       else {

           ViewHolderOne vaultItemHolder = (ViewHolderOne) holder;
           vaultItemHolder.name.setText(displayText);
           vaultItemHolder.name.setOnClickListener(new View.OnClickListener() {
               @Override
               public void onClick(View v) {
                   .......
               }
           });

       }

   }

   /****************  VIEW HOLDER 1 ******************//

   public class ViewHolderOne extends RecyclerView.ViewHolder {

       public TextView name;

       public ViewHolderOne(View itemView) {
       super(itemView);
       name = (TextView)itemView.findViewById(R.id.displayName);
       }
   }


  //****************  VIEW HOLDER 2 ******************//

  public class ViewHolderTwo extends RecyclerView.ViewHolder{

       public ViewHolderTwo(View itemView) {
       super(itemView);

           ..... Do something
       }
  }
}

GitHub Code:

Here is a project where I have implemented a RecyclerView with multiple ViewHolders.

Google Maps API v3 marker with label

In order to add a label to the map you need to create a custom overlay. The sample at http://blog.mridey.com/2009/09/label-overlay-example-for-google-maps.html uses a custom class, Layer, that inherits from OverlayView (which inherits from MVCObject) from the Google Maps API. He has a revised version (adds support for visibility, zIndex and a click event) which can be found here: http://blog.mridey.com/2011/05/label-overlay-example-for-google-maps.html

The following code is taken directly from Marc Ridey's Blog (the revised link above).

Layer class

// Define the overlay, derived from google.maps.OverlayView
function Label(opt_options) {
  // Initialization
  this.setValues(opt_options);


  // Label specific
  var span = this.span_ = document.createElement('span');
  span.style.cssText = 'position: relative; left: -50%; top: -8px; ' +
  'white-space: nowrap; border: 1px solid blue; ' +
  'padding: 2px; background-color: white';


  var div = this.div_ = document.createElement('div');
  div.appendChild(span);
  div.style.cssText = 'position: absolute; display: none';
};
Label.prototype = new google.maps.OverlayView;


// Implement onAdd
Label.prototype.onAdd = function() {
  var pane = this.getPanes().overlayImage;
  pane.appendChild(this.div_);


  // Ensures the label is redrawn if the text or position is changed.
  var me = this;
  this.listeners_ = [
    google.maps.event.addListener(this, 'position_changed', function() { me.draw(); }),
    google.maps.event.addListener(this, 'visible_changed', function() { me.draw(); }),
    google.maps.event.addListener(this, 'clickable_changed', function() { me.draw(); }),
    google.maps.event.addListener(this, 'text_changed', function() { me.draw(); }),
    google.maps.event.addListener(this, 'zindex_changed', function() { me.draw(); }),
    google.maps.event.addDomListener(this.div_, 'click', function() {
      if (me.get('clickable')) {
        google.maps.event.trigger(me, 'click');
      }
    })
  ];
};

// Implement onRemove
Label.prototype.onRemove = function() {
 this.div_.parentNode.removeChild(this.div_);

 // Label is removed from the map, stop updating its position/text.
 for (var i = 0, I = this.listeners_.length; i < I; ++i) {
   google.maps.event.removeListener(this.listeners_[i]);
 }
};

// Implement draw
Label.prototype.draw = function() {
 var projection = this.getProjection();
 var position = projection.fromLatLngToDivPixel(this.get('position'));

 var div = this.div_;
 div.style.left = position.x + 'px';
 div.style.top = position.y + 'px';
 div.style.display = 'block';

 this.span_.innerHTML = this.get('text').toString();
};

Usage

<html>
  <head>
    <meta http-equiv="content-type" content="text/html; charset=utf-8">
    <title>
      Label Overlay Example
    </title>
    <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
    <script type="text/javascript" src="label.js"></script>
    <script type="text/javascript">
      var marker;


      function initialize() {
        var latLng = new google.maps.LatLng(40, -100);


        var map = new google.maps.Map(document.getElementById('map_canvas'), {
          zoom: 5,
          center: latLng,
          mapTypeId: google.maps.MapTypeId.ROADMAP
        });


        marker = new google.maps.Marker({
          position: latLng,
          draggable: true,
          zIndex: 1,
          map: map,
          optimized: false
        });


        var label = new Label({
          map: map
        });
        label.bindTo('position', marker);
        label.bindTo('text', marker, 'position');
        label.bindTo('visible', marker);
        label.bindTo('clickable', marker);
        label.bindTo('zIndex', marker);


        google.maps.event.addListener(marker, 'click', function() { alert('Marker has been clicked'); })
        google.maps.event.addListener(label, 'click', function() { alert('Label has been clicked'); })
      }


      function showHideMarker() {
        marker.setVisible(!marker.getVisible());
      }


      function pinUnpinMarker() {
        var draggable = marker.getDraggable();
        marker.setDraggable(!draggable);
        marker.setClickable(!draggable);
      }
    </script>
  </head>
  <body onload="initialize()">
    <div id="map_canvas" style="height: 200px; width: 200px"></div>
    <button type="button" onclick="showHideMarker();">Show/Hide Marker</button>
    <button type="button" onclick="pinUnpinMarker();">Pin/Unpin Marker</button>
  </body>
</html>

SVN - Checksum mismatch while updating

I had a simllar problem. Main provider was antivirus "FortiClient" (antivirus + VPN CLient). When I disabled it - all update/checkout was made correctly

Join between tables in two different databases?

Yes, assuming the account has appropriate permissions you can use:

SELECT <...>
FROM A.table1 t1 JOIN B.table2 t2 ON t2.column2 = t1.column1;

You just need to prefix the table reference with the name of the database it resides in.

Centering in CSS Grid

Try using flex:

Plunker demo : https://plnkr.co/edit/nk02ojKuXD2tAqZiWvf9

/* Styles go here */

html,
body {
  margin: 0;
  padding: 0;
}

.container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 100vh;
  grid-gap: 0px 0px;
}

.left_bg {
  background-color: #3498db;
  grid-column: 1 / 1;
  grid-row: 1 / 1;
  z-index: 0;
  display: flex;
  justify-content: center;
  align-items: center;

}

.right_bg {
  background-color: #ecf0f1;
  grid-column: 2 / 2;
  grid_row: 1 / 1;
  z-index: 0;
  display: flex;
  justify-content: center;
  align-items: center;
}

.text {
  font-family: Raleway;
  font-size: large;
  text-align: center;
}

HTML

    <div class="container">
  <!--everything on the page-->

  <div class="left_bg">
    <!--left background color of the page-->
    <div class="text">
      <!--left side text content-->
      <p>Review my stuff</p>
    </div>
  </div>

  <div class="right_bg">
    <!--right background color of the page-->
    <div class="text">
      <!--right side text content-->
      <p>Hire me!</p>
    </div>
  </div>
</div>

What's the longest possible worldwide phone number I should consider in SQL varchar(length) for phone

In the GSM specification 3GPP TS 11.11, there are 10 bytes set aside in the MSISDN EF (6F40) for 'dialing number'. Since this is the GSM representation of a phone number, and it's usage is nibble swapped, (and there is always the possibility of parentheses) 22 characters of data should be plenty.

In my experience, there is only one instance of open/close parentheses, that is my reasoning for the above.

Delete first character of a string in Javascript

_x000D_

String.prototype.trimStartWhile = function(predicate) {_x000D_
    if (typeof predicate !== "function") {_x000D_
     return this;_x000D_
    }_x000D_
    let len = this.length;_x000D_
    if (len === 0) {_x000D_
        return this;_x000D_
    }_x000D_
    let s = this, i = 0;_x000D_
    while (i < len && predicate(s[i])) {_x000D_
     i++;_x000D_
    }_x000D_
    return s.substr(i)_x000D_
}_x000D_
_x000D_
let str = "0000000000ABC",_x000D_
    r = str.trimStartWhile(c => c === '0');_x000D_
    _x000D_
console.log(r);

_x000D_

Reference - What does this regex mean?

The Stack Overflow Regular Expressions FAQ

See also a lot of general hints and useful links at the regex tag details page.

Online tutorials

Quantifiers

Zero-or-more: *:greedy, *?:reluctant, *+:possessive
One-or-more: +:greedy, +?:reluctant, ++:possessive
?:optional (zero-or-one)
Min/max ranges (all inclusive): {n,m}:between n & m, {n,}:n-or-more, {n}:exactly n
Differences between greedy, reluctant (a.k.a. "lazy", "ungreedy") and possessive quantifier:
- Greedy vs. Reluctant vs. Possessive Quantifiers
- In-depth discussion on the differences between greedy versus non-greedy
- What's the difference between {n} and {n}?
- Can someone explain Possessive Quantifiers to me? php, perl, java, ruby
- Emulating possessive quantifiers .net
- Non-Stack Overflow references: From Oracle, regular-expressions.info

Character Classes

What is the difference between square brackets and parentheses?
[...]: any one character, [^...]: negated/any character but
[^] matches any one character including newlines javascript
[\w-[\d]] / [a-z-[qz]]: set subtraction .net, xml-schema, xpath, JGSoft
[\w&&[^\d]]: set intersection java, ruby 1.9+
[[:alpha:]]:POSIX character classes
Why do [^\\D2], [^[^0-9]2], [^2[^0-9]] get different results in Java? java
Shorthand:
- Digit: \d:digit, \D:non-digit
- Word character (Letter, digit, underscore): \w:word character, \W:non-word character
- Whitespace: \s:whitespace, \S:non-whitespace
Unicode categories (\p{L}, \P{L}, etc.)

Escape Sequences

Horizontal whitespace: \h:space-or-tab, \t:tab
Newlines:
- \r, \n:carriage return and line feed
- \R:generic newline php java-8
Negated whitespace sequences: \H:Non horizontal whitespace character, \V:Non vertical whitespace character, \N:Non line feed character pcre php5 java-8
Other: \v:vertical tab, \e:the escape character

Anchors

^:start of line/input, \b:word boundary, and \B:non-word boundary, $:end of line/input
\A:start of input, \Z:end of input php, perl, ruby
\z:the very end of input (\Z in Python) .net, php, pcre, java, ruby, icu, swift, objective-c
\G:start of match php, perl, ruby

(Also see "Flavor-Specific Information ? Java ? The functions in Matcher")

Groups

(...):capture group, (?:):non-capture group
- Why is my repeating capturing group only capturing the last match?
\1:backreference and capture-group reference, $1:capture group reference
- What's the meaning of a number after a backslash in a regular expression?
- \g<1>123:How to follow a numbered capture group, such as \1, with a number?: python
What does a subpattern (?i:regex) mean?
What does the 'P' in (?P<group_name>regexp) mean?
(?>):atomic group or independent group, (?|):branch reset
- Equivalent of branch reset in .NET/C# .net
Named capture groups:
- General named capturing group reference at regular-expressions.info
- java: (?<groupname>regex): Overview and naming rules (Non-Stack Overflow links)
- Other languages: (?P<groupname>regex) python, (?<groupname>regex) .net, (?<groupname>regex) perl, (?P<groupname>regex) and (?<groupname>regex) php

Lookarounds

Lookaheads: (?=...):positive, (?!...):negative
Lookbehinds: (?<=...):positive, (?<!...):negative (not supported by javascript)
Lookbehind limits in:
Lookbehind alternatives:
- Using \K php, perl (Flavors that support \K)
- Alternative regex module for Python python
  - The hacky way
  - JavaScript negative lookbehind equivalents ^{External link}

Modifiers

flag	modifier	flavors
`c`	current position	perl
`e`	expression	php perl
`g`	global	most
`i`	case-insensitive	most
`m`	multiline	php perl python javascript .net java
`m`	(non)multiline	ruby
`o`	once	perl ruby
`S`	study	php
`s`	single line	unsupported: javascript (workaround) \| ruby
`U`	ungreedy	php r
`u`	unicode	most
`x`	whitespace-extended	most
`y`	sticky ?	javascript

Other:

|:alternation (OR) operator, .:any character, [.]:literal dot character
What special characters must be escaped?
Control verbs (php and perl): (*PRUNE), (*SKIP), (*FAIL) and (*F)
- php only: (*BSR_ANYCRLF)
Recursion (php and perl): (?R), (?0) and (?1), (?-1), (?&groupname)

Common Tasks

Get a string between two curly braces: {...}
Match (or replace) a pattern except in situations s1, s2, s3...
How do I find all YouTube video ids in a string using a regex?
Validation:
- Internet: email addresses, URLs (host/port: regex and non-regex alternatives), passwords
- Numeric: a number, min-max ranges (such as 1-31), phone numbers, date
- Parsing HTML with regex: See "General Information > When not to use Regex"

Advanced Regex-Fu

Flavor-Specific Information

(Except for those marked with *, this section contains non-Stack Overflow links.)

Java
- Official documentation: Pattern Javadoc ?, Oracle's regular expressions tutorial ?
- The differences between functions in java.util.regex.Matcher:
  - matches()): The match must be anchored to both input-start and -end
  - find()): A match may be anywhere in the input string (substrings)
  - lookingAt(): The match must be anchored to input-start only
  - (For anchors in general, see the section "Anchors")
- The only java.lang.String functions that accept regular expressions: matches(s), replaceAll(s,s), replaceFirst(s,s), split(s), split(s,i)
- *An (opinionated and) detailed discussion of the disadvantages of and missing features in java.util.regex
.NET
- How to read a .NET regex with look-ahead, look-behind, capturing groups and back-references mixed together?
Official documentation:
- Boost regex engine: General syntax, Perl syntax (used by TextPad, Sublime Text, UltraEdit, ...???)
- JavaScript 1.5 general info and RegExp object
- .NET MySQL Oracle Perl5 version 18.2
- PHP: pattern syntax, preg_match
- Python: Regular expression operations, search vs match, how-to
- Rust: crate regex, struct regex::Regex
- Splunk: regex terminology and syntax and regex command
- Tcl: regex syntax, manpage, regexp command
- Visual Studio Find and Replace

General information

(Links marked with * are non-Stack Overflow links.)

Other general documentation resources: Learning Regular Expressions, *Regular-expressions.info, *Wikipedia entry, *RexEgg, Open-Directory Project
DFA versus NFA
Generating Strings matching regex
Books: Jeffrey Friedl's Mastering Regular Expressions
When to not use regular expressions:
- Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems. (blog post written by Stack Overflow's founder)*
- Do not use regex to parse HTML:
  - Don't. Please, just don't
  - Well, maybe...if you're really determined (other answers in this question are also good)

Examples of regex that can cause regex engine to fail

Why does this regular expression kill the Java regex engine?

Tools: Testers and Explainers

(This section contains non-Stack Overflow links.)

Owl Carousel, making custom navigation

If you want to use your own custom navigation elements,

For Owl Carousel 1

var owl = $('.owl-carousel');
owl.owlCarousel();
// Go to the next item
$('.customNextBtn').click(function() {
    owl.trigger('owl.prev');
})
// Go to the previous item
$('.customPrevBtn').click(function() {
    owl.trigger('owl.next');
})

For Owl Carousel 2

var owl = $('.owl-carousel');
owl.owlCarousel();
// Go to the next item
$('.customNextBtn').click(function() {
    owl.trigger('next.owl.carousel');
})
// Go to the previous item
$('.customPrevBtn').click(function() {
    // With optional speed parameter
    // Parameters has to be in square bracket '[]'
    owl.trigger('prev.owl.carousel', [300]);
})

Concat all strings inside a List<string> using LINQ

String.Join(delimiter, list);

is sufficient.

Change a Django form field to a hidden field

Firstly, if you don't want the user to modify the data, then it seems cleaner to simply exclude the field. Including it as a hidden field just adds more data to send over the wire and invites a malicious user to modify it when you don't want them to. If you do have a good reason to include the field but hide it, you can pass a keyword arg to the modelform's constructor. Something like this perhaps:

class MyModelForm(forms.ModelForm):
    class Meta:
        model = MyModel
    def __init__(self, *args, **kwargs):
        from django.forms.widgets import HiddenInput
        hide_condition = kwargs.pop('hide_condition',None)
        super(MyModelForm, self).__init__(*args, **kwargs)
        if hide_condition:
            self.fields['fieldname'].widget = HiddenInput()
            # or alternately:  del self.fields['fieldname']  to remove it from the form altogether.

Then in your view:

form = MyModelForm(hide_condition=True)

I prefer this approach to modifying the modelform's internals in the view, but it's a matter of taste.

How do I execute a *.dll file

While many people have pointed out that you can't execute dlls directly and should use rundll32.exe to execute exported functions instead, here is a screenshot of an actual dll file running just like an executable:

While you cannot run dll files directly, I suspect it is possible to run them from another process using a WinAPI function CreateProcess:

https://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx

How do I make an http request using cookies on Android?

It turns out that Google Android ships with Apache HttpClient 4.0, and I was able to figure out how to do it using the "Form based logon" example in the HttpClient docs:

https://github.com/apache/httpcomponents-client/blob/master/httpclient5/src/test/java/org/apache/hc/client5/http/examples/ClientFormLogin.java

import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.cookie.Cookie;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;

/**
 * A example that demonstrates how HttpClient APIs can be used to perform
 * form-based logon.
 */
public class ClientFormLogin {

    public static void main(String[] args) throws Exception {

        DefaultHttpClient httpclient = new DefaultHttpClient();

        HttpGet httpget = new HttpGet("https://portal.sun.com/portal/dt");

        HttpResponse response = httpclient.execute(httpget);
        HttpEntity entity = response.getEntity();

        System.out.println("Login form get: " + response.getStatusLine());
        if (entity != null) {
            entity.consumeContent();
        }
        System.out.println("Initial set of cookies:");
        List<Cookie> cookies = httpclient.getCookieStore().getCookies();
        if (cookies.isEmpty()) {
            System.out.println("None");
        } else {
            for (int i = 0; i < cookies.size(); i++) {
                System.out.println("- " + cookies.get(i).toString());
            }
        }

        HttpPost httpost = new HttpPost("https://portal.sun.com/amserver/UI/Login?" +
                "org=self_registered_users&" +
                "goto=/portal/dt&" +
                "gotoOnFail=/portal/dt?error=true");

        List <NameValuePair> nvps = new ArrayList <NameValuePair>();
        nvps.add(new BasicNameValuePair("IDToken1", "username"));
        nvps.add(new BasicNameValuePair("IDToken2", "password"));

        httpost.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));

        response = httpclient.execute(httpost);
        entity = response.getEntity();

        System.out.println("Login form get: " + response.getStatusLine());
        if (entity != null) {
            entity.consumeContent();
        }

        System.out.println("Post logon cookies:");
        cookies = httpclient.getCookieStore().getCookies();
        if (cookies.isEmpty()) {
            System.out.println("None");
        } else {
            for (int i = 0; i < cookies.size(); i++) {
                System.out.println("- " + cookies.get(i).toString());
            }
        }

        // When HttpClient instance is no longer needed, 
        // shut down the connection manager to ensure
        // immediate deallocation of all system resources
        httpclient.getConnectionManager().shutdown();        
    }
}

How to add Web API to an existing ASP.NET MVC 4 Web Application project?

The above solution works perfectly. I prefer to choose Web API option while selecting the project template as shown in the picture below

Note: The solution works with Visual Studio 2013 or higher. The original question was asked in 2012 and it is 2016, therefore adding a solution Visual Studio 2013 or higher.

How do I install soap extension?

I had the same problem, there was no extension=php_soap.dll in my php.ini But this was because I had copied the php.ini from a old and previous php version (not a good idea). I found the dll in the ext directory so I just could put it myself into the php.ini extension=php_soap.dll After Apache restart all worked with soap :)

How to pad a string with leading zeros in Python 3

Since python 3.6 you can use fstring :

>>> length = 1
>>> print(f'length = {length:03}')
length = 001

A method to reverse effect of java String.split()?

For Android: in android.text.TextUtils there are methods:

public static String join (CharSequence delimiter, Iterable tokens)
public static String join (CharSequence delimiter, Object[] tokens)

Returns a string containing the tokens joined by delimiters.

tokens -- an array objects to be joined. Strings will be formed from the objects by calling object.toString().

How I can check if an object is null in ruby on rails 2?

You can use the simple not flag to validate that. Example

if !@objectname

This will return true if @objectname is nil. You should not use dot operator or a nil value, else it will throw

*** NoMethodError Exception: undefined method `isNil?' for nil:NilClass

An ideal nil check would be like:

!@objectname || @objectname.nil? || @objectname.empty?

"The following SDK components were not installed: sys-img-x86-addon-google_apis-google-22 and addon-google_apis-google-22"

I was getting an "out of space" error, which left me scratching my head as I had plenty of disk space, until I realized that it ran out of space on /tmp, which on Arch Linux is mounted on a tmpfs with a size limit.

Difference between SelectedItem, SelectedValue and SelectedValuePath

Every control that uses Collections to store data have SelectedValue, SelectedItem property. Examples of these controls are ListBox, Dropdown, RadioButtonList, CheckBoxList.

To be more specific if you literally want to retrieve Text of Selected Item then you can write:

ListBox1.SelectedItem.Text;

Your ListBox1 can also return Text using SelectedValue property if value has set to that before. But above is more effective way to get text.

Now, the value is something that is not visible to user but it is used mostly to store in database. We don't insert Text of ListBox1, however we can insert it also, but we used to insert value of selected item. To get value we can use

ListBox1.SelectedValue

Source

Programs & Examples On #Reboot

How can I get the Windows last reboot reason

Is there a command to restart computer into safe mode?

How is the java memory pool divided?

Heap memory

Non-heap memory

android: move a view on touch move (ACTION_MOVE)

jQuery UI DatePicker to show month year only

jQuery calculate sum of values in all text fields

Descending order by date filter in AngularJs

Redirect using AngularJS

How to style HTML5 range input to have different color before and after slider?

Grant all on a specific schema in the db to a group role in PostgreSQL

To Be Conservative

Access to the Schema

Existing Objects Versus Future

How can I send an inner <div> to the bottom of its parent <div>?

Display current time in 12 hour format with AM/PM

How to change int into int64?

Total number of items defined in an enum

the MySQL service on local computer started and then stopped

Sourcetree - undo unpushed commits

How to set the style -webkit-transform dynamically using JavaScript?

Apply style to parent if it has child with css

How to do SVN Update on my project using the command line

How do I make an Event in the Usercontrol and have it handled in the Main Form?

Detect current device with UI_USER_INTERFACE_IDIOM() in Swift

how to set length of an column in hibernate with maximum length

Changing directory in Google colab (breaking out of the python interpreter)

Can't Load URL: The domain of this URL isn't included in the app's domains

failed to open stream: No such file or directory in

Shared-memory objects in multiprocessing

Android check permission for LocationManager

How to parse a JSON file in swift?

Is background-color:none valid CSS?

RHEL 6 - how to install 'GLIBC_2.14' or 'GLIBC_2.15'?

Elegant ways to support equivalence ("equality") in Python classes

Locking a file in Python

How do I pass parameters into a PHP script through a webpage?

How do I search for an object by its ObjectId in the mongo console?

White space showing up on right side of page when background image should extend full length of page

What is the difference between baud rate and bit rate?

How to manage exceptions thrown in filters in Spring?

How to get the difference between two arrays of objects in JavaScript

Getting View's coordinates relative to the root layout

Fastest way to flatten / un-flatten nested JSON objects

How do I print bold text in Python?

How to append data to a json file?

Is there a REAL performance difference between INT and VARCHAR primary keys?

'namespace' but is used like a 'type'

Custom HTTP Authorization Header

Adding and removing extensionattribute to AD object

Error message "unreported exception java.io.IOException; must be caught or declared to be thrown"

Regex for password must contain at least eight characters, at least one number and both lower and uppercase letters and special characters

What is the official "preferred" way to install pip and virtualenv systemwide?

How to check if there exists a process with a given pid in Python?

Remove a CLASS for all child elements

How to get process details from its pid

$(form).ajaxSubmit is not a function

How do you fix the "element not interactable" exception?

How can I get a specific parameter from location.search?

C# testing to see if a string is an integer?

Play infinitely looping video on-load in HTML5

Looping Over Result Sets in MySQL

Visual Studio Code open tab in new window

How to list processes attached to a shared memory segment in linux?

How to implement an STL-style iterator and avoid common pitfalls?

SQL Server: how to create a stored procedure

How to close a thread from within?

MySQL and GROUP_CONCAT() maximum length

Changing an element's ID with jQuery

Php artisan make:auth command is not defined

Exception in thread "main" java.util.NoSuchElementException

What is the difference between gravity and layout_gravity in Android?

Best way to convert string to bytes in Python 3?

Gcc error: gcc: error trying to exec 'cc1': execvp: No such file or directory

How does the SQL injection from the "Bobby Tables" XKCD comic work?

SQL query to make all data in a column UPPER CASE?

A Bit About Collation

Compiling Java 7 code via Maven