SyntaxFix

Programs & Examples On #Wireframe

Plotting a 3d cube, a sphere and a vector in Matplotlib

For drawing just the arrow, there is an easier method:-

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
fig = plt.figure()
ax = fig.gca(projection='3d')
ax.set_aspect("equal")

#draw the arrow
ax.quiver(0,0,0,1,1,1,length=1.0)

plt.show()

quiver can actually be used to plot multiple vectors at one go. The usage is as follows:- [ from http://matplotlib.org/mpl_toolkits/mplot3d/tutorial.html?highlight=quiver#mpl_toolkits.mplot3d.Axes3D.quiver]

quiver(X, Y, Z, U, V, W, **kwargs)

Arguments:

X, Y, Z: The x, y and z coordinates of the arrow locations

U, V, W: The x, y and z components of the arrow vectors

The arguments could be array-like or scalars.

Keyword arguments:

length: [1.0 | float] The length of each quiver, default to 1.0, the unit is the same with the axes

arrow_length_ratio: [0.3 | float] The ratio of the arrow head with respect to the quiver, default to 0.3

pivot: [ ‘tail’ | ‘middle’ | ‘tip’ ] The part of the arrow that is at the grid point; the arrow rotates about this point, hence the name pivot. Default is ‘tail’

normalize: [False | True] When True, all of the arrows will be the same length. This defaults to False, where the arrows will be different lengths depending on the values of u,v,w.

How to make a text box have rounded corners?

This can be done with CSS3:

<input type="text" />

input
{
  -moz-border-radius: 15px;
 border-radius: 15px;
    border:solid 1px black;
    padding:5px;
}

http://jsfiddle.net/UbSkn/1/

However, an alternative would be to put the input inside a div with a rounded background, and no border on the input

Software Design vs. Software Architecture

I view architecture as Patrick Karcher does - the big picture. For example, you can provide the architecture to a building, view its structural support, the windows, entries and exits, water drainage, etc. But you have not "designed" the floor layout's, cubicle positions etc.

So while you've architected the building you have not designed the layout of each office. I think the same holds true for software.

You could view designing the layout, as "architecting the layout" though ...

How do you render primitives as wireframes in OpenGL?

 
glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );

to switch on,

glPolygonMode( GL_FRONT_AND_BACK, GL_FILL );

to go back to normal.

Note that things like texture-mapping and lighting will still be applied to the wireframe lines if they're enabled, which can look weird.

Can I make a function available in every controller in angular?

You basically have two options, either define it as a service, or place it on your root scope. I would suggest that you make a service out of it to avoid polluting the root scope. You create a service and make it available in your controller like this:

<!doctype html>
<html ng-app="myApp">
<head>
    <script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
    <script src="http://code.angularjs.org/1.1.2/angular.min.js"></script>
    <script type="text/javascript">
    var myApp = angular.module('myApp', []);

    myApp.factory('myService', function() {
        return {
            foo: function() {
                alert("I'm foo!");
            }
        };
    });

    myApp.controller('MainCtrl', ['$scope', 'myService', function($scope, myService) {
        $scope.callFoo = function() {
            myService.foo();
        }
    }]);
    </script>
</head>
<body ng-controller="MainCtrl">
    <button ng-click="callFoo()">Call foo</button>
</body>
</html>

If that's not an option for you, you can add it to the root scope like this:

<!doctype html>
<html ng-app="myApp">
<head>
    <script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
    <script src="http://code.angularjs.org/1.1.2/angular.min.js"></script>
    <script type="text/javascript">
    var myApp = angular.module('myApp', []);

    myApp.run(function($rootScope) {
        $rootScope.globalFoo = function() {
            alert("I'm global foo!");
        };
    });

    myApp.controller('MainCtrl', ['$scope', function($scope){

    }]);
    </script>
</head>
<body ng-controller="MainCtrl">
    <button ng-click="globalFoo()">Call global foo</button>
</body>
</html>

That way, all of your templates can call globalFoo() without having to pass it to the template from the controller.

Create File If File Does Not Exist

You don't even need to do the check manually, File.Open does it for you. Try:

using (StreamWriter sw = new StreamWriter(File.Open(path, System.IO.FileMode.Append))) 
{

Ref: http://msdn.microsoft.com/en-us/library/system.io.filemode.aspx

How do you copy the contents of an array to a std::vector in C++ without looping?

If you can construct the vector after you've gotten the array and array size, you can just say:

std::vector<ValueType> vec(a, a + n);

...assuming a is your array and n is the number of elements it contains. Otherwise, std::copy() w/resize() will do the trick.

I'd stay away from memcpy() unless you can be sure that the values are plain-old data (POD) types.

Also, worth noting that none of these really avoids the for loop--it's just a question of whether you have to see it in your code or not. O(n) runtime performance is unavoidable for copying the values.

Finally, note that C-style arrays are perfectly valid containers for most STL algorithms--the raw pointer is equivalent to begin(), and (ptr + n) is equivalent to end().

Git: Create a branch from unstaged/uncommitted changes on master

Try:

git stash
git checkout -b new-branch
git stash apply

Using ffmpeg to change framerate

Simply specify the desired framerate in "-r " option before the input file:

ffmpeg -y -r 24 -i seeing_noaudio.mp4 seeing.mp4

Options affect the next file AFTER them. "-r" before an input file forces to reinterpret its header as if the video was encoded at the given framerate. No recompression is necessary. There was a small utility avifrate.exe to patch avi file headers directly to change the framerate. ffmpeg command above essentially does the same, but has to copy the entire file.

Android Studio 3.0 Execution failed for task: unable to merge dex

I Have Done and fixed this issue by just doing this jobs in my code

Open ->build.gradle Change value from 

compile 'com.google.code.gson:gson:2.6.1'

to

compile 'com.google.code.gson:gson:2.8.2'

How do I style appcompat-v7 Toolbar like Theme.AppCompat.Light.DarkActionBar?

Edit: After updating to appcompat-v7:22.1.1 and using AppCompatActivity instead of ActionBarActivity my styles.xml looks like:

<style name="AppBaseTheme" parent="Theme.AppCompat.Light">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
    <item name="theme">@style/ThemeOverlay.AppCompat.Dark.ActionBar</item>
</style>

Note: This means I am using a Toolbar provided by the framework (NOT included in an XML file).

This worked for me:
styles.xml file:

<style name="AppBaseTheme" parent="Theme.AppCompat.Light">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
    <item name="windowActionBar">false</item>
    <item name="theme">@style/ThemeOverlay.AppCompat.Dark.ActionBar</item>
</style>

Update: A quote from Gabriele Mariotti's blog.

With the new Toolbar you can apply a style and a theme. They are different! The style is local to the Toolbar view, for example the background color. The app:theme is instead global to all ui elements inflated in the Toolbar, for example the color of the title and icons.

How can I get last characters of a string

I am sure this will work....

var string1="myfile.pdf"
var esxtenion=string1.substr(string1.length-4)

The value of extension will be ".pdf"

How do you trigger a block after a delay, like -performSelector:withObject:afterDelay:?

(verified on Xcode 11.3.1 in June 2020)

Xcode provides a code snippet to do this. You just have to enter the delay value and the code you wish to run after the delay.

  1. click on the + button at the top right of Xcode.
  2. search for after
  3. It will return only 1 search result, which is the desired snippet (see screenshot). Double click it and you're good to go.

screenshot illustrating how to get the snippet from within Xcode itself

Openstreetmap: embedding map in webpage (like Google Maps)

I would also take a look at CloudMade's developer tools. They offer a beautifully styled OSM base map service, an OpenLayers plugin, and even their own light-weight, very fast JavaScript mapping client. They also host their own routing service, which you mentioned as a possible requirement. They have great documentation and examples.

Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

That true,Mustafa....its working..its point to two layout

  1. setContentView(R.layout.your_layout)
  2. v23(your_layout).

You should take Button both activity layout...
solve this problem successfully

Check if element at position [x] exists in the list

 
if(list.ElementAtOrDefault(2) != null)
{
   // logic
}

ElementAtOrDefault() is part of the System.Linq namespace.

Although you have a List, so you can use list.Count > 2.

HttpServletRequest - Get query string parameters, no form data

As the other answers state there is no way getting query string parameters using servlet api.

So, I think the best way to get query parameters is parsing the query string yourself. ( It is more complicated iterating over parameters and checking if query string contains the parameter)

I wrote below code to get query string parameters. Using apache StringUtils and ArrayUtils which supports CSV separated query param values as well.

Example: username=james&username=smith&password=pwd1,pwd2 will return

password : [pwd1, pwd2] (length = 2)

username : [james, smith] (length = 2)

public static Map<String, String[]> getQueryParameters(HttpServletRequest request) throws UnsupportedEncodingException {
    Map<String, String[]> queryParameters = new HashMap<>();
    String queryString = request.getQueryString();
    if (StringUtils.isNotEmpty(queryString)) {
        queryString = URLDecoder.decode(queryString, StandardCharsets.UTF_8.toString());
        String[] parameters = queryString.split("&");
        for (String parameter : parameters) {
            String[] keyValuePair = parameter.split("=");
            String[] values = queryParameters.get(keyValuePair[0]);
            //length is one if no value is available.
            values = keyValuePair.length == 1 ? ArrayUtils.add(values, "") :
                    ArrayUtils.addAll(values, keyValuePair[1].split(",")); //handles CSV separated query param values.
            queryParameters.put(keyValuePair[0], values);
        }
    }
    return queryParameters;
}

How to open a new file in vim in a new window

Check out gVim. You can launch that in its own window.

gVim makes it really easy to manage multiple open buffers graphically.

You can also do the usual :e to open a new file, CTRL+^ to toggle between buffers, etc...

Another cool feature lets you open a popup window that lists all the buffers you've worked on.

This allows you to switch between open buffers with a single click.

To do this, click on the Buffers menu at the top and click the dotted line with the scissors.

enter image description here

Otherwise you can just open a new tab from your terminal session and launch vi from there.

You can usually open a new tab from terminal with CTRL+T or CTRL+ALT+T

Once vi is launched, it's easy to open new files and switch between them.

Restoring MySQL database from physical files

Yes it is! Just add them to your database-folder ( depending on the OS ) and run a command such as "MySQL Fix Permissions". This re-stored the database. See too it that the correct permissions are set on the files aswell.

jquery background-color change on focus and blur

Tested Code:

$("input").css("background","red");

Complete:

$('input:text').focus(function () {
    $(this).css({ 'background': 'Black' });
});

$('input:text').blur(function () {
    $(this).css({ 'background': 'red' });
});

Tested in version:

jquery-1.9.1.js
jquery-ui-1.10.3.js

Adding items to end of linked list

 
public static Node insertNodeAtTail(Node head,Object data) {
               Node node = new Node(data);
                 node.next = null;
                if (head == null){
                    return node;
                }
                else{
                    Node temp = head;
                    while(temp.next != null){
                        temp = temp.next;
                    }
                    temp.next = node; 
                    return head;
                }        
    }

make an ID in a mysql table auto_increment (after the fact)

This worked for me (i wanted to make id primary and set auto increment)

ALTER TABLE table_name CHANGE id id INT PRIMARY KEY AUTO_INCREMENT;

Why do I get the "Unhandled exception type IOException"?

add "throws IOException" to your method like this:

public static void main(String args[]) throws  IOException{

        FileReader reader=new FileReader("db.properties");

        Properties p=new Properties();
        p.load(reader);


    }

Excel VBA Open workbook, perform actions, save as, close

After discussion posting updated answer:

Option Explicit
Sub test()

    Dim wk As String, yr As String
    Dim fname As String, fpath As String
    Dim owb As Workbook

    With Application
        .DisplayAlerts = False
        .ScreenUpdating = False
        .EnableEvents = False
    End With

    wk = ComboBox1.Value
    yr = ComboBox2.Value
    fname = yr & "W" & wk
    fpath = "C:\Documents and Settings\jammil\Desktop\AutoFinance\ProjectControl\Data"

    On Error GoTo ErrorHandler
    Set owb = Application.Workbooks.Open(fpath & "\" & fname)

    'Do Some Stuff

    With owb
        .SaveAs fpath & Format(Date, "yyyymm") & "DB" & ".xlsx", 51
        .Close
    End With

    With Application
        .DisplayAlerts = True
        .ScreenUpdating = True
        .EnableEvents = True
    End With

Exit Sub
ErrorHandler: If MsgBox("This File Does Not Exist!", vbRetryCancel) = vbCancel Then

Else: Call Clear

End Sub

Error Handling:

You could try something like this to catch a specific error:

    On Error Resume Next
    Set owb = Application.Workbooks.Open(fpath & "\" & fname)
    If Err.Number = 1004 Then
    GoTo FileNotFound
    Else
    End If

    ...
    Exit Sub
    FileNotFound: If MsgBox("This File Does Not Exist!", vbRetryCancel) = vbCancel Then

    Else: Call Clear

Export to xls using angularjs

I had this problem and I made a tool to export an HTML table to CSV file. The problem I had with FileSaver.js is that this tool grabs the table with html format, this is why some people can't open the file in excel or google. All you have to do is export the js file and then call the function. This is the github url https://github.com/snake404/tableToCSV if someone has the same problem.

How to stop/shut down an elasticsearch node?

Considering you have 3 nodes.

Prepare your cluster

export ES_HOST=localhost:9200

# Disable shard allocation
curl -X PUT "$ES_HOST/_cluster/settings" -H 'Content-Type: application/json' -d'
{
  "persistent": {
    "cluster.routing.allocation.enable": "none"
  }
}
'

# Stop non-essential indexing and perform a synced flush
curl -X POST "$ES_HOST/_flush/synced"

Stop elasticsearch service in each node

# check nodes
export ES_HOST=localhost:9200
curl -X GET "$ES_HOST/_cat/nodes"

# node 1
systemctl stop elasticsearch.service

# node 2
systemctl stop elasticsearch.service

# node 3
systemctl stop elasticsearch.service

Restarting cluster again

# start
systemctl start elasticsearch.service

# Reenable shard allocation once the node has joined the cluster
curl -X PUT "$ES_HOST/_cluster/settings" -H 'Content-Type: application/json' -d'
{
  "persistent": {
    "cluster.routing.allocation.enable": null
  }
}
'

Tested on Elasticseach 6.5

Source:

  1. https://www.elastic.co/guide/en/elasticsearch/reference/6.5/stopping-elasticsearch.html
  2. https://www.elastic.co/guide/en/elasticsearch/reference/6.5/rolling-upgrades.html

Close application and launch home screen on Android

Say you have activity stack like A>B>C>D>E. You are at activity D, and you want to close your app. This is what you wil do -

In Activity from where you want to close (Activity D)-

Intent intent = new Intent(D.this,A.class);
intent.putExtra("exit", "exit");
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP| Intent.FLAG_ACTIVITY_SINGLE_TOP);
startActivity(intent);

In your RootActivity (ie your base activity, here Activity A) - 

@Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        if (intent.hasExtra("exit")) {
            setIntent(intent);
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (getIntent() != null) {
            if (("exit").equalsIgnoreCase(getIntent().getStringExtra(("exit")))) {
                onBackPressed();
            }
        }
    }

onNewIntent is used because if activity is alive, it will get the first intent that started it. Not the new one. For more detail - Documentation

CSS rule to apply only if element has BOTH classes

If you need a progmatic solution this should work in jQuery:

$(".abc.xyz").css("width", 200);

Get the last insert id with doctrine 2?

Here i post my code, after i have pushed myself for one working day to find this solution.

Function to get the last saved record : 

private function getLastId($query) {
        $conn = $this->getDoctrine()->getConnection();
        $stmt = $conn->prepare($query);
        $stmt->execute();
        $lastId = $stmt->fetch()['id'];
        return $lastId;
    }

Another Function which call the above function

private function clientNum() {
        $lastId = $this->getLastId("SELECT id FROM client ORDER BY id DESC LIMIT 1");
        $noClient = 'C' . sprintf("%06d", $lastId + 1); // C000002 if the last record ID is 1
        return $noClient;
    }

refresh leaflet map: map container is already initialized

Before initializing map check for is the map is already initiated or not

var container = L.DomUtil.get('map');

if(container != null){

container._leaflet_id = null;

}

It works for me

Disable developer mode extensions pop up in Chrome

Can't be disabled. Quoting: "Sorry, we know it is annoying, but you the malware writers..."

Your only options are: adapt your automated tests to this new behavior, or upload the offending script to Chrome Web Store (which can be done in an "unlisted" fashion).

Array of PHP Objects

Although all the answers given are correct, in fact they do not completely answer the question which was about using the [] construct and more generally filling the array with objects.

A more relevant answer can be found in how to build arrays of objects in PHP without specifying an index number? which clearly shows how to solve the problem.

With android studio no jvm found, JAVA_HOME has been set

It says that it should be a 64-bit JDK. I have a feeling that you installed (at a previous time) a 32-bit version of Java. The path for all 32-bit applications in Windows 7 and Vista is:

C:\Program Files (x86)\

You were setting the JAVA_HOME variable to the 32-bit version of Java. Set your JAVA_HOME variable to the following:

C:\Program Files\Java\jdk1.7.0_45

If that does not work, check that the JDK version is 1.7.0_45. If not, change the JAVA_HOME variable to (with JAVAVERSION as the Java version number:

C:\Program Files\Java\jdkJAVAVERSION

What version of JBoss I am running?

The version of JBoss should also be visible in the boot log file. Standard install would have that (for linux) in

/var/log/jboss/boot.log

$ head boot.log

08:30:07,477 INFO  [Server] Starting JBoss (MX MicroKernel)...
08:30:07,478 INFO  [Server] Release ID: JBoss [Trinity] 4.2.2.GA (build: SVNTag=JBoss_4_2_2_GA date=200710221139)
08:30:07,478 DEBUG [Server] Using config: org.jboss.system.server.ServerConfigImpl@4277158a
08:30:07,478 DEBUG [Server] Server type: class org.jboss.system.server.ServerImpl
08:30:07,478 DEBUG [Server] Server loaded through: org.jboss.system.server.NoAnnotationURLClassLoader
08:30:07,478 DEBUG [Server] Boot URLs:

so required info int the above case is

Release ID: JBoss [Trinity] 4.2.2.GA (build: SVNTag=JBoss_4_2_2_GA date=200710221139)

Going to a specific line number using Less in Unix

To open at a specific line straight from the command line, use:

less +320123 filename

If you want to see the line numbers too:

less +320123 -N filename

You can also choose to display a specific line of the file at a specific line of the terminal, for when you need a few lines of context. For example, this will open the file with line 320123 on the 10th line of the terminal:

less +320123 -j 10 filename

"java.lang.OutOfMemoryError: PermGen space" in Maven build

I have found a solution of git bash command when you try to build war using git mvn clean install for “java.lang.OutOfMemoryError: PermGen space” in Maven build error come

use below command first 

$ export MAVEN_OPTS="-Xmx512m -Xss32m"

then use your mvn command to clean install /build war file

$ mvn clean install

NOTE: you don't need -XX:MaxPermSize argument in MAVEN_OPTS when your are using jdk1.8
Java HotSpot(TM) Client VM warning: ignoring option MaxPermSize=XXXm; support was removed in 8.0

How to disable or enable viewpager swiping in android

Best solution for me. -First, you create a class like this:

public class CustomViewPager extends ViewPager {
  private Boolean disable = false;
  public CustomViewPager(Context context) {
      super(context);
  }
  public CustomViewPager(Context context, AttributeSet attrs){
      super(context,attrs);
  }
  @Override
  public boolean onInterceptTouchEvent(MotionEvent event) {
     return !disable && super.onInterceptTouchEvent(event);
  }

  @Override
  public boolean onTouchEvent(MotionEvent event) {
     return !disable && super.onTouchEvent(event);
  }

  public void disableScroll(Boolean disable){
      //When disable = true not work the scroll and when disble = false work the scroll
      this.disable = disable;
  }
}

-Then change this in your layout:<android.support.v4.view.ViewPager for this<com.mypackage.CustomViewPager

-Finally, you can disable it:view_pager.disableScroll(true); or enable it: view_pager.disableScroll(false);

I hope that this help you :)

Why are you not able to declare a class as static in Java?

Everything we code in java goes into a class. Whenever we run a class JVM instantiates an object. JVM can create a number of objects, by definition Static means you have the same set of copy to all objects.

So, if Java would have allowed the top class to be static whenever you run a program it creates an Object and keeps overriding on to the same Memory Location.

If You are just replacing the object every time you run it whats the point of creating it?

So that is the reason Java got rid of the static for top-Level Class.

There might be more concrete reasons but this made much logical sense to me.

Open a new tab on button click in AngularJS

Proper HTML way: just surround your button with anchor element and add attribute target="_blank". It is as simple as that:

<a ng-href="{{yourDynamicURL}}" target="_blank">
    <h1>Open me in new Tab</h1>
</a>

where you can set in the controller:

$scope.yourDynamicURL = 'https://stackoverflow.com';

Can someone give an example of cosine similarity, in a very simple, graphical way?

I'm guessing you are more interested in getting some insight into "why" the cosine similarity works (why it provides a good indication of similarity), rather than "how" it is calculated (the specific operations used for the calculation). If your interest is in the latter, see the reference indicated by Daniel in this post, as well as a related SO Question.

To explain both the how and even more so the why, it is useful, at first, to simplify the problem and to work only in two dimensions. Once you get this in 2D, it is easier to think of it in three dimensions, and of course harder to imagine in many more dimensions, but by then we can use linear algebra to do the numeric calculations and also to help us think in terms of lines / vectors / "planes" / "spheres" in n dimensions, even though we can't draw these.

So, in two dimensions: with regards to text similarity this means that we would focus on two distinct terms, say the words "London" and "Paris", and we'd count how many times each of these words is found in each of the two documents we wish to compare. This gives us, for each document, a point in the the x-y plane. For example, if Doc1 had Paris once, and London four times, a point at (1,4) would present this document (with regards to this diminutive evaluation of documents). Or, speaking in terms of vectors, this Doc1 document would be an arrow going from the origin to point (1,4). With this image in mind, let's think about what it means for two documents to be similar and how this relates to the vectors.

VERY similar documents (again with regards to this limited set of dimensions) would have the very same number of references to Paris, AND the very same number of references to London, or maybe, they could have the same ratio of these references. A Document, Doc2, with 2 refs to Paris and 8 refs to London, would also be very similar, only with maybe a longer text or somehow more repetitive of the cities' names, but in the same proportion. Maybe both documents are guides about London, only making passing references to Paris (and how uncool that city is ;-) Just kidding!!!.

Now, less similar documents may also include references to both cities, but in different proportions. Maybe Doc2 would only cite Paris once and London seven times.

Back to our x-y plane, if we draw these hypothetical documents, we see that when they are VERY similar, their vectors overlap (though some vectors may be longer), and as they start to have less in common, these vectors start to diverge, to have a wider angle between them.

By measuring the angle between the vectors, we can get a good idea of their similarity, and to make things even easier, by taking the Cosine of this angle, we have a nice 0 to 1 or -1 to 1 value that is indicative of this similarity, depending on what and how we account for. The smaller the angle, the bigger (closer to 1) the cosine value, and also the higher the similarity.

At the extreme, if Doc1 only cites Paris and Doc2 only cites London, the documents have absolutely nothing in common. Doc1 would have its vector on the x-axis, Doc2 on the y-axis, the angle 90 degrees, Cosine 0. In this case we'd say that these documents are orthogonal to one another.

Adding dimensions:
With this intuitive feel for similarity expressed as a small angle (or large cosine), we can now imagine things in 3 dimensions, say by bringing the word "Amsterdam" into the mix, and visualize quite well how a document with two references to each would have a vector going in a particular direction, and we can see how this direction would compare to a document citing Paris and London three times each, but not Amsterdam, etc. As said, we can try and imagine the this fancy space for 10 or 100 cities. It's hard to draw, but easy to conceptualize.

I'll wrap up just by saying a few words about the formula itself. As I've said, other references provide good information about the calculations.

First in two dimensions. The formula for the Cosine of the angle between two vectors is derived from the trigonometric difference (between angle a and angle b):

cos(a - b) = (cos(a) * cos(b)) + (sin (a) * sin(b))

This formula looks very similar to the dot product formula:

Vect1 . Vect2 =  (x1 * x2) + (y1 * y2)

where cos(a) corresponds to the x value and sin(a) the y value, for the first vector, etc. The only problem, is that x, y, etc. are not exactly the cos and sin values, for these values need to be read on the unit circle. That's where the denominator of the formula kicks in: by dividing by the product of the length of these vectors, the x and y coordinates become normalized.

Find character position and update file name

If you're working with actual files (as opposed to some sort of string data), how about the following?

$files | % { "$($_.BaseName -replace '_[^_]+$','')$($_.Extension)" }

(or use _.+$ if you want to cut everything from the first underscore.)

Select top 2 rows in Hive

Here I think it's worth mentioning SORT BY and ORDER BY both clauses and why they different,

SELECT * FROM <table_name> SORT BY <column_name> DESC LIMIT 2

If you are using SORT BY clause it sort data per reducer which means if you have more than one MapReduce task it will result partially ordered data. On the other hand, the ORDER BY clause will result in ordered data for the final Reduce task. To understand more please refer to this link.

SELECT * FROM <table_name> ORDER BY <column_name> DESC LIMIT 2

Note: Finally, Even though the accepted answer contains SORT BY clause, I mostly prefer to use ORDER BY clause for the general use case to avoid any data loss.

How to remove the arrows from input[type="number"] in Opera

Those arrows are part of the Shadow DOM, which are basically DOM elements on your page which are hidden from you. If you're new to the idea, a good introductory read can be found here.

For the most part, the Shadow DOM saves us time and is good. But there are instances, like this question, where you want to modify it.

You can modify these in Webkit now with the right selectors, but this is still in the early stages of development. The Shadow DOM itself has no unified selectors yet, so the webkit selectors are proprietary (and it isn't just a matter of appending -webkit, like in other cases).

Because of this, it seems likely that Opera just hasn't gotten around to adding this yet. Finding resources about Opera Shadow DOM modifications is tough, though. A few unreliable internet sources I've found all say or suggest that Opera doesn't currently support Shadow DOM manipulation.

I spent a bit of time looking through the Opera website to see if there'd be any mention of it, along with trying to find them in Dragonfly...neither search had any luck. Because of the silence on this issue, and the developing nature of the Shadow DOM + Shadow DOM manipulation, it seems to be a safe conclusion that you just can't do it in Opera, at least for now.

Splitting words into letters in Java

 
 char[] result = "Stack Me 123 Heppa1 oeu".toCharArray();

array.select() in javascript

There's also Array.find() in ES6 which returns the first matching element it finds.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find

const myArray = [1, 2, 3]

const myElement = myArray.find((element) => element === 2)

console.log(myElement)
// => 2

In Perl, what is the difference between a .pm (Perl module) and .pl (Perl script) file?

At the very core, the file extension you use makes no difference as to how perl interprets those files.

However, putting modules in .pm files following a certain directory structure that follows the package name provides a convenience. So, if you have a module Example::Plot::FourD and you put it in a directory Example/Plot/FourD.pm in a path in your @INC, then use and require will do the right thing when given the package name as in use Example::Plot::FourD.

The file must return true as the last statement to indicate successful execution of any initialization code, so it's customary to end such a file with 1; unless you're sure it'll return true otherwise. But it's better just to put the 1;, in case you add more statements.

If EXPR is a bareword, the require assumes a ".pm" extension and replaces "::" with "/" in the filename for you, to make it easy to load standard modules. This form of loading of modules does not risk altering your namespace.

All use does is to figure out the filename from the package name provided, require it in a BEGIN block and invoke import on the package. There is nothing preventing you from not using use but taking those steps manually.

For example, below I put the Example::Plot::FourD package in a file called t.pl, loaded it in a script in file s.pl.

C:\Temp> cat t.pl
package Example::Plot::FourD;

use strict; use warnings;

sub new { bless {} => shift }

sub something { print "something\n" }

"Example::Plot::FourD"

C:\Temp> cat s.pl
#!/usr/bin/perl
use strict; use warnings;

BEGIN {
    require 't.pl';
}

my $p = Example::Plot::FourD->new;
$p->something;


C:\Temp> s
something

This example shows that module files do not have to end in 1, any true value will do.

"Call to undefined function mysql_connect()" after upgrade to php-7

From the PHP Manual:

Warning This extension was deprecated in PHP 5.5.0, and it was removed in PHP 7.0.0. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide. Alternatives to this function include:

mysqli_connect()

PDO::__construct()

use MySQLi or PDO

<?php
$con = mysqli_connect('localhost', 'username', 'password', 'database');

Private properties in JavaScript ES6 classes

I realize there are dozens of answers here. I want to share my solution, which ensures true private variables in ES6 classes and in older JS.

var MyClass = (function() {
    var $ = new WeakMap();
    function priv(self) {
       var r = $.get(self);
       if (!r) $.set(self, r={});
       return r;
    }

    return class { /* use $(this).prop inside your class */ } 
}();

Privacy is ensured by the fact that the outside world don't get access to $.

When the instance goes away, the WeakMap will release the data.

This definitely works in plain Javascript, and I believe they work in ES6 classes but I haven't tested that $ will be available inside the scope of member methods.

How to access data/data folder in Android device?

To backup from Android to Desktop

Open command line cmd and run this: adb backup -f C:\Intel\xxx.ab -noapk your.app.package. Do not enter password and click on Backup my data. Make sure not to save on drive C root. You may be denied. This is why I saved on C:\Intel.

To extract the *.ab file

  1. Go here and download: https://sourceforge.net/projects/adbextractor/
  2. Extract the downloaded file and navigate to folder where you extracted.
  3. run this with your own file names: java -jar abe.jar unpack c:\Intel\xxx.ab c:\Intel\xxx.tar

What does AND 0xFF do?

Anding an integer with 0xFF leaves only the least significant byte. For example, to get the first byte in a short s, you can write s & 0xFF. This is typically referred to as "masking". If byte1 is either a single byte type (like uint8_t) or is already less than 256 (and as a result is all zeroes except for the least significant byte) there is no need to mask out the higher bits, as they are already zero.

See tristopiaPatrick Schlüter's answer below when you may be working with signed types. When doing bitwise operations, I recommend working only with unsigned types.

What is the best way to programmatically detect porn images?

The BrightCloud web service API is perfect for this. It's a REST API for doing website lookups just like this. It contains a very large and very accurate web filtering DB and one of the categories, Adult, has over 10M porn sites identified!

Remove Last Comma from a string

 
function removeLastComma(str) {
   return str.replace(/,(\s+)?$/, '');   
}

Source file 'Properties\AssemblyInfo.cs' could not be found

This rings a bell. I came across a similar problem in the past,

  • if you expand Properties folder of the project can you see 'AssemblyInfo.cs' if not that is where the problem is. An assembly info file consists of all of the build options for the project, including version, company name, GUID, compilers options....etc

You can generate an assemblyInfo.cs by right clicking the project and chosing properties. In the application tab fill in the details and press save, this will generate the assemblyInfo.cs file for you. If you build your project after that, it should work.

Cheers, Tarun

Update 2016-07-08:

For Visual Studio 2010 through the most recent version (2015 at time of writing), LandedGently's comment still applies:

After you select project Properties and the Application tab as @Tarun mentioned, there is a button "Assembly Information..." which opens another dialog. You need to at least fill in the Title here. VS will add the GUID and versions, but if the title is empty, it will not create the AssemblyInfo.cs file.

How to get changes from another branch

  1. go to the master branch our-team

    • git checkout our-team

  2. pull all the new changes from our-team branch

    • git pull

  3. go to your branch featurex

    • git checkout featurex

  4. merge the changes of our-team branch into featurex branch

    • git merge our-team
    • or git cherry-pick {commit-hash} if you want to merge specific commits

  5. push your changes with the changes of our-team branch

    • git push

Note: probably you will have to fix conflicts after merging our-team branch into featurex branch before pushing

What is the best way to conditionally apply a class?

You can use this npm package. It handles everything and has options for static and conditional classes based on a variable or a function.

// Support for string arguments
getClassNames('class1', 'class2');

// support for Object
getClassNames({class1: true, class2 : false});

// support for all type of data
getClassNames('class1', 'class2', ['class3', 'class4'], { 
    class5 : function() { return false; },
    class6 : function() { return true; }
});

<div className={getClassNames({class1: true, class2 : false})} />

Convert timestamp long to normal date format

java.time

    ZoneId usersTimeZone = ZoneId.of("Asia/Tashkent");
    Locale usersLocale = Locale.forLanguageTag("ga-IE");
    DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM)
            .withLocale(usersLocale);

    long microsSince1970 = 1_512_345_678_901_234L;
    long secondsSince1970 = TimeUnit.MICROSECONDS.toSeconds(microsSince1970);
    long remainingMicros = microsSince1970 - TimeUnit.SECONDS.toMicros(secondsSince1970);
    ZonedDateTime dateTime = Instant.ofEpochSecond(secondsSince1970, 
                    TimeUnit.MICROSECONDS.toNanos(remainingMicros))
            .atZone(usersTimeZone);
    String dateTimeInUsersFormat = dateTime.format(formatter);
    System.out.println(dateTimeInUsersFormat);

The above snippet prints:

4 Noll 2017 05:01:18

“Noll” is Gaelic for December, so this should make your user happy. Except there may be very few Gaelic speaking people living in Tashkent, so please specify the user’s correct time zone and locale yourself.

I am taking seriously that you got microseconds from your database. If second precision is fine, you can do without remainingMicros and just use the one-arg Instant.ofEpochSecond(), which will make the code a couple of lines shorter. Since Instant and ZonedDateTime do support nanosecond precision, I found it most correct to keep the full precision of your timestamp. If your timestamp was in milliseconds rather than microseconds (which they often are), you may just use Instant.ofEpochMilli().

The answers using Date, Calendar and/or SimpleDateFormat were fine when this question was asked 7 years ago. Today those classes are all long outdated, and we have so much better in java.time, the modern Java date and time API.

For most uses I recommend you use the built-in localized formats as I do in the code. You may experiment with passing SHORT, LONG or FULL for format style. Yo may even specify format style for the date and for the time of day separately using an overloaded ofLocalizedDateTime method. If a specific format is required (this was asked in a duplicate question), you can have that:

    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss, dd/MM/uuuu");

Using this formatter instead we get

05:01:18, 04/12/2017

Link: Oracle tutorial: Date Time explaining how to use java.time.

Maximum number of records in a MySQL database table

There is no limit. It only depends on your free memory and system maximum file size. But that doesn't mean you shouldn't take precautionary measure in tackling memory usage in your database. Always create a script that can delete rows that are out of use or that will keep total no of rows within a particular figure, say a thousand.

Namespace for [DataContract]

I solved this problem by adding C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\System.Runtime.Serialization.dll in the reference

How can I inspect element in chrome when right click is disabled?

Sure, you can open the devtools with Ctrl+Shift+I, and then click the inspect element button (square with the arrow)

Android requires compiler compliance level 5.0 or 6.0. Found '1.7' instead. Please use Android Tools > Fix Project Properties

Following worked for me

Enable project-specific settings and set the compliance level to 1.6

How can you do that?

In your Eclipse Package Explorer 3rd click on your project and select properties. Properties Window will open. Select Java Compiler on the left panel of the window. Now Enable project specific settings and set the Complier compliance level to 1.6. Select Apply and then OK.

How do I spool to a CSV formatted file using SQLPLUS?

It's crude, but:

set pagesize 0 linesize 500 trimspool on feedback off echo off

select '"' || empno || '","' || ename || '","' || deptno || '"' as text
from emp

spool emp.csv
/
spool off

bootstrap datepicker today as default

I changed code in line 1796 file 'bootstrap-datetimepicker.js'. It's worked for me

enter image description here

Why is document.write considered a "bad practice"?

Here's my twopence worth, in general you shouldn't use document.write for heavy lifting, but there is one instance where it is definitely useful:

http://www.quirksmode.org/blog/archives/2005/06/three_javascrip_1.html

I discovered this recently trying to create an AJAX slider gallery. I created two nested divs, and applied width/height and overflow: hidden to the outer <div> with JS. This was so that in the event that the browser had JS disabled, the div would float to accommodate the images in the gallery - some nice graceful degradation.

Thing is, as with the article above, this JS hijacking of the CSS didn't kick in until the page had loaded, causing a momentary flash as the div was loaded. So I needed to write a CSS rule, or include a sheet, as the page loaded.

Obviously, this won't work in XHTML, but since XHTML appears to be something of a dead duck (and renders as tag soup in IE) it might be worth re-evaluating your choice of DOCTYPE...

Custom ImageView with drop shadow

My dirty solution:

private static Bitmap getDropShadow3(Bitmap bitmap) {

    if (bitmap==null) return null;
    int think = 6;
    int w = bitmap.getWidth();
    int h = bitmap.getHeight();

    int newW = w - (think);
    int newH = h - (think);

    Bitmap.Config conf = Bitmap.Config.ARGB_8888;
    Bitmap bmp = Bitmap.createBitmap(w, h, conf);
    Bitmap sbmp = Bitmap.createScaledBitmap(bitmap, newW, newH, false);

    Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    Canvas c = new Canvas(bmp);

    // Right
    Shader rshader = new LinearGradient(newW, 0, w, 0, Color.GRAY, Color.LTGRAY, Shader.TileMode.CLAMP);
    paint.setShader(rshader);
    c.drawRect(newW, think, w, newH, paint);

    // Bottom
    Shader bshader = new LinearGradient(0, newH, 0, h, Color.GRAY, Color.LTGRAY, Shader.TileMode.CLAMP);
    paint.setShader(bshader);
    c.drawRect(think, newH, newW  , h, paint);

    //Corner
    Shader cchader = new LinearGradient(0, newH, 0, h, Color.LTGRAY, Color.LTGRAY, Shader.TileMode.CLAMP);
    paint.setShader(cchader);
    c.drawRect(newW, newH, w  , h, paint);


    c.drawBitmap(sbmp, 0, 0, null);

    return bmp;
}

result: enter image description here

regex error - nothing to repeat

Beyond the bug that was discovered and fixed, I'll just note that the error message sre_constants.error: nothing to repeat is a bit confusing. I was trying to use r'?.*' as a pattern, and thought it was complaining for some strange reason about the *, but the problem is actually that ? is a way of saying "repeat zero or one times". So I needed to say r'\?.*'to match a literal ?

Amazon AWS Filezilla transfer permission denied

To allow user ec2-user (Amazon AWS) write access to the public web directory (/var/www/html),
enter this command via Putty or Terminal, as the root user sudo:

chown -R ec2-user /var/www/html

Make sure permissions on that entire folder were correct:

chmod -R 755 /var/www/html

Doc's:

Setting up amazon ec2-instances

Connect to Amazon EC2 file directory using Filezilla and SFTP (Video)

Understanding and Using File Permissions

Adding a slide effect to bootstrap dropdown

Intro

As of the time of writing, the original answer is now 8 years old. Still I feel like there isn't yet a proper solution to the original question.

Bootstrap has gone a long way since then and is now at 4.5.2. This answer addresses this very version.

The problem with all other solutions so far

The issue with all the other answers is, that while they hook into show.bs.dropdown / hide.bs.dropdown, the follow-up events shown.bs.dropdown / hidden.bs.dropdown are either fired too early (animation still ongoing) or they don't fire at all because they were suppressed (e.preventDefault()).

A clean solution

Since the implementation of show() and hide() in Bootstraps Dropdown class share some similarities, I've grouped them together in toggleDropdownWithAnimation() when mimicing the original behaviour and added little QoL helper functions to showDropdownWithAnimation() and hideDropdownWithAnimation().
toggleDropdownWithAnimation() creates a shown.bs.dropdown / hidden.bs.dropdown event the same way Bootstrap does it. This event is then fired after the animation completed - just like you would expect.

/**
 * Toggle visibility of a dropdown with slideDown / slideUp animation.
 * @param {JQuery} $containerElement The outer dropdown container. This is the element with the .dropdown class.
 * @param {boolean} show Show (true) or hide (false) the dropdown menu.
 * @param {number} duration Duration of the animation in milliseconds
 */
function toggleDropdownWithAnimation($containerElement, show, duration = 300): void {
    // get the element that triggered the initial event
    const $toggleElement = $containerElement.find('.dropdown-toggle');
    // get the associated menu
    const $dropdownMenu = $containerElement.find('.dropdown-menu');
    // build jquery event for when the element has been completely shown
    const eventArgs = {relatedTarget: $toggleElement};
    const eventType = show ? 'shown' : 'hidden';
    const eventName = `${eventType}.bs.dropdown`;
    const jQueryEvent = $.Event(eventName, eventArgs);

    if (show) {
        // mimic bootstraps element manipulation
        $containerElement.addClass('show');
        $dropdownMenu.addClass('show');
        $toggleElement.attr('aria-expanded', 'true');
        // put focus on initial trigger element
        $toggleElement.trigger('focus');
        // start intended animation
        $dropdownMenu
            .stop() // stop any ongoing animation
            .hide() // hide element to fix initial state of element for slide down animation
            .slideDown(duration, () => {
            // fire 'shown' event
            $($toggleElement).trigger(jQueryEvent);
        });
    }
    else {
        // mimic bootstraps element manipulation
        $containerElement.removeClass('show');
        $dropdownMenu.removeClass('show');
        $toggleElement.attr('aria-expanded', 'false');
        // start intended animation
        $dropdownMenu
            .stop() // stop any ongoing animation
            .show() // show element to fix initial state of element for slide up animation
            .slideUp(duration, () => {

            // fire 'hidden' event
            $($toggleElement).trigger(jQueryEvent);
        });
    }
}

/**
 * Show a dropdown with slideDown animation.
 * @param {JQuery} $containerElement The outer dropdown container. This is the element with the .dropdown class.
 * @param {number} duration Duration of the animation in milliseconds
 */
function showDropdownWithAnimation($containerElement, duration = 300) {
    toggleDropdownWithAnimation($containerElement, true, duration);
}

/**
 * Hide a dropdown with a slideUp animation.
 * @param {JQuery} $containerElement The outer dropdown container. This is the element with the .dropdown class.
 * @param {number} duration Duration of the animation in milliseconds
 */
function hideDropdownWithAnimation($containerElement, duration = 300) {
    toggleDropdownWithAnimation($containerElement, false, duration);
}

Bind Event Listeners

Now that we have written proper callbacks for showing / hiding a dropdown with an animation, let's actually bind these to the correct events.

A common mistake I've seen a lot in other answers is binding event listeners to elements directly. While this works fine for DOM elements present at the time the event listener is registered, it does not bind to elements added later on.

That's why you are generally better off binding directly to the document:

$(function () {

    /* Hook into the show event of a bootstrap dropdown */
    $(document).on('show.bs.dropdown', '.dropdown', function (e) {
        // prevent bootstrap from executing their event listener
        e.preventDefault();
        
        showDropdownWithAnimation($(this));
    });

    /* Hook into the hide event of a bootstrap dropdown */
    $(document).on('hide.bs.dropdown', '.dropdown', function (e) {
        // prevent bootstrap from executing their event listener
        e.preventDefault();
          
        hideDropdownWithAnimation($(this));
    });

});

How to convert currentTimeMillis to a date in Java?

 
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(timeStamp);

int mYear = calendar.get(Calendar.YEAR);
int mMonth = calendar.get(Calendar.MONTH);
int mDay = calendar.get(Calendar.DAY_OF_MONTH);

add a temporary column with a value

I giving you an example in wich the TABLE registrofaena doesn't have the column called minutos. Minutos is created and it content is a result of divide demora/60, in other words, i created a column to show the values of the delay in minutes.

This is the query:

SELECT idfaena,fechahora,demora, demora/60 as minutos,comentario 
FROM registrofaena  
WHERE fecha>='2018-10-17' AND comentario <> '' 
ORDER BY idfaena ASC;

This is the view:

This is the result

Convert A String (like testing123) To Binary In Java

The usual way is to use String#getBytes() to get the underlying bytes and then present those bytes in some other form (hex, binary whatever).

Note that getBytes() uses the default charset, so if you want the string converted to some specific character encoding, you should use getBytes(String encoding) instead, but many times (esp when dealing with ASCII) getBytes() is enough (and has the advantage of not throwing a checked exception).

For specific conversion to binary, here is an example:

  String s = "foo";
  byte[] bytes = s.getBytes();
  StringBuilder binary = new StringBuilder();
  for (byte b : bytes)
  {
     int val = b;
     for (int i = 0; i < 8; i++)
     {
        binary.append((val & 128) == 0 ? 0 : 1);
        val <<= 1;
     }
     binary.append(' ');
  }
  System.out.println("'" + s + "' to binary: " + binary);

Running this example will yield:

'foo' to binary: 01100110 01101111 01101111

PHP Get name of current directory

$myVar = str_replace('/', '', $_SERVER[REQUEST_URI]);

libs/images/index.php
Result: images

Amazon Linux: apt-get: command not found

Use yum with sudo for Amazon Linux 2 AMI (HVM), SSD Volume Type

Example: Try to install wsgi with apache at aws instance

sudo yum install python3-pip apache2 libapache2-mod-wsgi-py3

How to reshape data from long to wide format

much easier way!

devtools::install_github("yikeshu0611/onetree") #install onetree package

library(onetree)
widedata=reshape_toWide(data = dat1,id = "name",j = "numbers",value.var.prefix = "value")
widedata

        name     value1     value2     value3     value4
   firstName  0.3407997 -0.7033403 -0.3795377 -0.7460474
  secondName -0.8981073 -0.3347941 -0.5013782 -0.1745357

if you want to go back from wide to long, only change Wide to Long, and no changes in objects.

reshape_toLong(data = widedata,id = "name",j = "numbers",value.var.prefix = "value")

        name numbers      value
   firstName       1  0.3407997
  secondName       1 -0.8981073
   firstName       2 -0.7033403
  secondName       2 -0.3347941
   firstName       3 -0.3795377
  secondName       3 -0.5013782
   firstName       4 -0.7460474
  secondName       4 -0.1745357

Difference between __getattr__ vs __getattribute__

New-style classes are ones that subclass "object" (directly or indirectly). They have a __new__ class method in addition to __init__ and have somewhat more rational low-level behavior.

Usually, you'll want to override __getattr__ (if you're overriding either), otherwise you'll have a hard time supporting "self.foo" syntax within your methods.

Extra info: http://www.devx.com/opensource/Article/31482/0/page/4

Could not execute menu item (internal error)[Exception] - When changing PHP version from 5.3.1 to 5.2.9

  1. Like you installed older version of PHP do the same with Apache. I picked version 2.0.63 and then I was able to run WAMP Server with PHP 5.2.9 with no problems.

  2. I also read that it's problem with 64-bit version of WAMP.

What's the difference between a single precision and double precision floating point operation?

All have explained in great detail and nothing I could add further. Though I would like to explain it in Layman's Terms or plain ENGLISH

1.9 is less precise than 1.99
1.99 is less precise than 1.999
1.999 is less precise than 1.9999

.....

A variable, able to store or represent "1.9" provides less precision than the one able to hold or represent 1.9999. These Fraction can amount to a huge difference in large calculations.

Spring AMQP + RabbitMQ 3.3.5 ACCESS_REFUSED - Login was refused using authentication mechanism PLAIN

I was facing this issue due to empty space at the end of the password(spring.rabbitmq.password=rabbit ) in spring boot application.properties got resolved on removing the empty space. Hope this checklist helps some one facing this issue.

How to multi-line "Replace in files..." in Notepad++

This is a subjective opinion, but I think a text editor shouldn't do everything and the kitchen sink. I prefer lightweight flexible and powerful (in their specialized fields) editors. Although being mostly a Windows user, I like the Unix philosophy of having lot of specialized tools that you can pipe together (like the UnxUtils) rather than a monster doing everything, but not necessarily as you would like it!

Find in files is on the border of these extra features, but useful when you can double-click on a found line to open the file at the right line. Note that initially, in SciTE it was just a Tools call to grep or equivalent!
FTP is very close to off topic, although it can be seen as an extended open/save dialog.
Replace in files is too much IMO: it is dangerous (you can mess lot of files at once) if you have no preview, etc. I would rather use a specialized tool I chose, perhaps among those in Multi line search and replace tool.

To answer the question, looking at N++, I see a Run menu where you can launch any tool, with assignment of a name and shortcut key. I see also Plugins > NppExec, which seems able to launch stuff like sed (not tried it).

How to request Location Permission at runtime

check this code from MainActivity

 // Check location permission is granted - if it is, start
// the service, otherwise request the permission
fun checkOrAskLocationPermission(callback: () -> Unit) {
    // Check GPS is enabled
    val lm = getSystemService(Context.LOCATION_SERVICE) as LocationManager
    if (!lm.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
        Toast.makeText(this, "Please enable location services", Toast.LENGTH_SHORT).show()
        buildAlertMessageNoGps(this)
        return
    }

    // Check location permission is granted - if it is, start
    // the service, otherwise request the permission
    val permission = ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
    if (permission == PackageManager.PERMISSION_GRANTED) {
        callback.invoke()
    } else {
        // callback will be inside the activity's onRequestPermissionsResult(
        ActivityCompat.requestPermissions(
            this,
            arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
            PERMISSIONS_REQUEST
        )
    }
}

plus 

   override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults)
    if (requestCode == PERMISSIONS_REQUEST) {
        if (grantResults[0] == PackageManager.PERMISSION_GRANTED){
              // Permission ok. Do work.
         }
    }
}

plus

 fun buildAlertMessageNoGps(context: Context) {
    val builder = AlertDialog.Builder(context);
    builder.setMessage("Your GPS is disabled. Do you want to enable it?")
        .setCancelable(false)
        .setPositiveButton("Yes") { _, _ -> context.startActivity(Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS)) }
        .setNegativeButton("No") { dialog, _ -> dialog.cancel(); }
    val alert = builder.create();
    alert.show();
}

usage

checkOrAskLocationPermission() {
            // Permission ok. Do work.
        }

Using CSS for a fade-in effect on page load

Method 1:

If you are looking for a self-invoking transition then you should use CSS 3 Animations. They aren't supported either, but this is exactly the kind of thing they were made for.

CSS

#test p {
    margin-top: 25px;
    font-size: 21px;
    text-align: center;

    -webkit-animation: fadein 2s; /* Safari, Chrome and Opera > 12.1 */
       -moz-animation: fadein 2s; /* Firefox < 16 */
        -ms-animation: fadein 2s; /* Internet Explorer */
         -o-animation: fadein 2s; /* Opera < 12.1 */
            animation: fadein 2s;
}

@keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* Firefox < 16 */
@-moz-keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* Safari, Chrome and Opera > 12.1 */
@-webkit-keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* Internet Explorer */
@-ms-keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* Opera < 12.1 */
@-o-keyframes fadein {
    from { opacity: 0; }
    to   { opacity: 1; }
}

Demo

Browser Support

All modern browsers and Internet Explorer 10 (and later): http://caniuse.com/#feat=css-animation


Method 2:

Alternatively, you can use jQuery (or plain JavaScript; see the third code block) to change the class on load:

jQuery

$("#test p").addClass("load");?

CSS

#test p {
    opacity: 0;
    font-size: 21px;
    margin-top: 25px;
    text-align: center;

    -webkit-transition: opacity 2s ease-in;
       -moz-transition: opacity 2s ease-in;
        -ms-transition: opacity 2s ease-in;
         -o-transition: opacity 2s ease-in;
            transition: opacity 2s ease-in;
}

#test p.load {
    opacity: 1;
}

Plain JavaScript (not in the demo)

document.getElementById("test").children[0].className += " load";

Demo

Browser Support

All modern browsers and Internet Explorer 10 (and later): http://caniuse.com/#feat=css-transitions


Method 3:

Or, you can use the method that .Mail uses:

jQuery

$("#test p").delay(1000).animate({ opacity: 1 }, 700);?

CSS

#test p {
    opacity: 0;
    font-size: 21px;
    margin-top: 25px;
    text-align: center;
}

Demo

Browser Support

jQuery 1.x: All modern browsers and Internet Explorer 6 (and later): http://jquery.com/browser-support/
jQuery 2.x: All modern browsers and Internet Explorer 9 (and later): http://jquery.com/browser-support/

This method is the most cross-compatible as the target browser does not need to support CSS 3 transitions or animations.

How can I undo git reset --hard HEAD~1?

Example of IRL case:

$ git fsck --lost-found

Checking object directories: 100% (256/256), done.
Checking objects: 100% (3/3), done.
dangling blob 025cab9725ccc00fbd7202da543f556c146cb119
dangling blob 84e9af799c2f5f08fb50874e5be7fb5cb7aa7c1b
dangling blob 85f4d1a289e094012819d9732f017c7805ee85b4
dangling blob 8f654d1cd425da7389d12c17dd2d88d318496d98
dangling blob 9183b84bbd292dcc238ca546dab896e073432933
dangling blob 1448ee51d0ea16f259371b32a557b60f908d15ee
dangling blob 95372cef6148d980ab1d7539ee6fbb44f5e87e22
dangling blob 9b3bf9fb1ee82c6d6d5ec9149e38fe53d4151fbd
dangling blob 2b21002ca449a9e30dbb87e535fbd4e65bac18f7
dangling blob 2fff2f8e4ea6408ac84a8560477aa00583002e66
dangling blob 333e76340b59a944456b4befd0e007c2e23ab37b
dangling blob b87163c8def315d40721e592f15c2192a33816bb
dangling blob c22aafb90358f6bf22577d1ae077ad89d9eea0a7
dangling blob c6ef78dd64c886e9c9895e2fc4556e69e4fbb133
dangling blob 4a71f9ff8262701171d42559a283c751fea6a201
dangling blob 6b762d368f44ddd441e5b8eae6a7b611335b49a2
dangling blob 724d23914b48443b19eada79c3eb1813c3c67fed
dangling blob 749ffc9a412e7584245af5106e78167b9480a27b
dangling commit f6ce1a403399772d4146d306d5763f3f5715cb5a    <- it's this one

$ git show f6ce1a403399772d4146d306d5763f3f5715cb5a

commit f6ce1a403399772d4146d306d5763f3f5715cb5a
Author: Stian Gudmundsen Høiland <[email protected]>
Date:   Wed Aug 15 08:41:30 2012 +0200

    *MY COMMIT MESSAGE IS DISPLAYED HERE*

diff --git a/Some.file b/Some.file
new file mode 100644
index 0000000..15baeba
--- /dev/null
+++ b/Some.file
*THE WHOLE COMMIT IS DISPLAYED HERE*

$ git rebase f6ce1a403399772d4146d306d5763f3f5715cb5a

First, rewinding head to replay your work on top of it...
Fast-forwarded master to f6ce1a403399772d4146d306d5763f3f5715cb5a.

How to handle command-line arguments in PowerShell

You are reinventing the wheel. Normal PowerShell scripts have parameters starting with -, like script.ps1 -server http://devserver

Then you handle them in param section in the beginning of the file.

You can also assign default values to your params, read them from console if not available or stop script execution:

 param (
    [string]$server = "http://defaultserver",
    [Parameter(Mandatory=$true)][string]$username,
    [string]$password = $( Read-Host "Input password, please" )
 )

Inside the script you can simply

write-output $server

since all parameters become variables available in script scope.

In this example, the $server gets a default value if the script is called without it, script stops if you omit the -username parameter and asks for terminal input if -password is omitted.

Update: You might also want to pass a "flag" (a boolean true/false parameter) to a PowerShell script. For instance, your script may accept a "force" where the script runs in a more careful mode when force is not used.

The keyword for that is [switch] parameter type:

 param (
    [string]$server = "http://defaultserver",
    [string]$password = $( Read-Host "Input password, please" ),
    [switch]$force = $false
 )

Inside the script then you would work with it like this:

if ($force) {
  //deletes a file or does something "bad"
}

Now, when calling the script you'd set the switch/flag parameter like this:

.\yourscript.ps1 -server "http://otherserver" -force

If you explicitly want to state that the flag is not set, there is a special syntax for that

.\yourscript.ps1 -server "http://otherserver" -force:$false

Links to relevant Microsoft documentation (for PowerShell 5.0; tho versions 3.0 and 4.0 are also available at the links):

Edit line thickness of CSS 'underline' attribute

Another way to do this is using ":after" (pseudo-element) on the element you want to underline.

h2{
  position:relative;
  display:inline-block;
  font-weight:700;
  font-family:arial,sans-serif;
  text-transform:uppercase;
  font-size:3em;
}
h2:after{
  content:"";
  position:absolute;
  left:0;
  bottom:0;
  right:0;
  margin:auto;
  background:#000;
  height:1px;

}

Syntax error: Illegal return statement in JavaScript

This can happen in ES6 if you use the incorrect (older) syntax for static methods:

export default class MyClass
{
    constructor()
    {
       ...
    }

    myMethod()
    {
       ...
    }
}

MyClass.someEnum = {Red: 0, Green: 1, Blue: 2}; //works

MyClass.anotherMethod() //or
MyClass.anotherMethod = function()
{
   return something; //doesn't work
}

Whereas the correct syntax is:

export default class MyClass
{
    constructor()
    {
       ...
    }

    myMethod()
    {
       ...
    }

    static anotherMethod()
    {
       return something; //works
    }
}

MyClass.someEnum = {Red: 0, Green: 1, Blue: 2}; //works

How to get all elements inside "div" that starts with a known text

With modern browsers, this is easy without jQuery:

document.getElementById('yourParentDiv').querySelectorAll('[id^="q17_"]');

The querySelectorAll takes a selector (as per CSS selectors) and uses it to search children of the 'yourParentDiv' element recursively. The selector uses ^= which means "starts with".

Note that all browsers released since June 2009 support this.

Why do we have to specify FromBody and FromUri?

When a parameter has [FromBody], Web API uses the Content-Type header to select a formatter. In this example, the content type is "application/json" and the request body is a raw JSON string (not a JSON object).

At most one parameter is allowed to read from the message body. So this will not work:

// Caution: Will not work!    
public HttpResponseMessage Post([FromBody] int id, [FromBody] string name) { ... }

The reason for this rule is that the request body might be stored in a non-buffered stream that can only be read once.

Please go through the website for more details: https://docs.microsoft.com/en-us/aspnet/web-api/overview/formats-and-model-binding/parameter-binding-in-aspnet-web-api

AWS Lambda import module error in python

Please add below one after Import requests

import boto3

What I can see that is missing in your code.

JavaScript: function returning an object

I would take those directions to mean:

  function makeGamePlayer(name,totalScore,gamesPlayed) {
        //should return an object with three keys:
        // name
        // totalScore
        // gamesPlayed

         var obj = {  //note you don't use = in an object definition
             "name": name,
             "totalScore": totalScore,
             "gamesPlayed": gamesPlayed
          }
         return obj;
    }

How do you replace all the occurrences of a certain character in a string?

You really should have multiple input, e.g. one for firstname, middle names, lastname and another one for age. If you want to have some fun though you could try:

>>> input_given="join smith 25"
>>> chars="".join([i for i in input_given if not i.isdigit()])
>>> age=input_given.translate(None,chars)
>>> age
'25'
>>> name=input_given.replace(age,"").strip()
>>> name
'join smith'

This would of course fail if there is multiple numbers in the input. a quick check would be:

assert(age in input_given)

and also:

assert(len(name)<len(input_given))

Java; String replace (using regular expressions)?

 
import java.util.regex.PatternSyntaxException;

// (:?\d+) \* x\^(:?\d+)
// 
// Options: ^ and $ match at line breaks
// 
// Match the regular expression below and capture its match into backreference number 1 «(:?\d+)»
//    Match the character “:” literally «:?»
//       Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
//    Match a single digit 0..9 «\d+»
//       Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
// Match the character “ ” literally « »
// Match the character “*” literally «\*»
// Match the characters “ x” literally « x»
// Match the character “^” literally «\^»
// Match the regular expression below and capture its match into backreference number 2 «(:?\d+)»
//    Match the character “:” literally «:?»
//       Between zero and one times, as many times as possible, giving back as needed (greedy) «?»
//    Match a single digit 0..9 «\d+»
//       Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
try {
    String resultString = subjectString.replaceAll("(?m)(:?\\d+) \\* x\\^(:?\\d+)", "$1x<sup>$2</sup>");
} catch (PatternSyntaxException ex) {
    // Syntax error in the regular expression
} catch (IllegalArgumentException ex) {
    // Syntax error in the replacement text (unescaped $ signs?)
} catch (IndexOutOfBoundsException ex) {
    // Non-existent backreference used the replacement text
}

ASP.NET MVC Page Won't Load and says "The resource cannot be found"

For me its solved follow the following steps :

One reason for this occur is if you don't have a start page or wrong start page set under your web project's properties. So do this:

1- Right click on your MVC project

2- Choose "Properties"

3- Select the "Web" tab

4- Select "Specific Page"

Assuming you have a controller called HomeController and an action method called Index, enter "home/index" in to the text box corresponding to the "Specific Page" radio button.

Now, if you launch your web application, it will take you to the view rendered by the HomeController's Index action method.

A process crashed in windows .. Crash dump location

http://support.microsoft.com/kb/931673

There are Registry changes you can make to explicitly select where the crash dump file resides, otherwise %localappdata%\Microsoft\Windows\WER is the default location. I assume that %localappdata% is defined differently for a user or a service running under System. You will need to enable WER I believe.

Given an array of numbers, return array of products of all other numbers (no division)

 
{-
Recursive solution using sqrt(n) subsets. Runs in O(n).

Recursively computes the solution on sqrt(n) subsets of size sqrt(n). 
Then recurses on the product sum of each subset.
Then for each element in each subset, it computes the product with
the product sum of all other products.
Then flattens all subsets.

Recurrence on the run time is T(n) = sqrt(n)*T(sqrt(n)) + T(sqrt(n)) + n

Suppose that T(n) ≤ cn in O(n).

T(n) = sqrt(n)*T(sqrt(n)) + T(sqrt(n)) + n
    ≤ sqrt(n)*c*sqrt(n) + c*sqrt(n) + n
    ≤ c*n + c*sqrt(n) + n
    ≤ (2c+1)*n
    ∈ O(n)

Note that ceiling(sqrt(n)) can be computed using a binary search 
and O(logn) iterations, if the sqrt instruction is not permitted.
-}

otherProducts [] = []
otherProducts [x] = [1]
otherProducts [x,y] = [y,x]
otherProducts a = foldl' (++) [] $ zipWith (\s p -> map (*p) s) solvedSubsets subsetOtherProducts
    where 
      n = length a

      -- Subset size. Require that 1 < s < n.
      s = ceiling $ sqrt $ fromIntegral n

      solvedSubsets = map otherProducts subsets
      subsetOtherProducts = otherProducts $ map product subsets

      subsets = reverse $ loop a []
          where loop [] acc = acc
                loop a acc = loop (drop s a) ((take s a):acc)

How to iterate through a list of objects in C++

-> it works like pointer u don't have to use *

for( list<student>::iterator iter= data.begin(); iter != data.end(); iter++ )
cout<<iter->name; //'iter' not 'it'

Split string based on regex

You could use a lookahead:

re.split(r'[ ](?=[A-Z]+\b)', input)

This will split at every space that is followed by a string of upper-case letters which end in a word-boundary.

Note that the square brackets are only for readability and could as well be omitted.

If it is enough that the first letter of a word is upper case (so if you would want to split in front of Hello as well) it gets even easier:

re.split(r'[ ](?=[A-Z])', input)

Now this splits at every space followed by any upper-case letter.

Reading in double values with scanf in c

Use the %lf format specifier to read a double:

double a;
scanf("%lf",&a);

Wikipedia has a decent reference for available format specifiers.

You'll need to use the %lf format specifier to print out the results as well:

printf("%lf %lf",a,b);

How to remove all click event handlers using jQuery?

 
$('#saveBtn').off('click').on('click',function(){
   saveQuestion(id)
});

Use jquery's off and on

Is it safe to delete a NULL pointer?

To complement ruslik's answer, in C++14 you can use this construction:

delete std::exchange(heapObject, nullptr);

Accessing private member variables from prototype-defined functions

Was playing around with this today and this was the only solution I could find without using Symbols. Best thing about this is it can actually all be completely private.

The solution is based around a homegrown module loader which basically becomes the mediator for a private storage cache (using a weak map). 

   const loader = (function() {
        function ModuleLoader() {}

    //Static, accessible only if truly needed through obj.constructor.modules
    //Can also be made completely private by removing the ModuleLoader prefix.
    ModuleLoader.modulesLoaded = 0;
    ModuleLoader.modules = {}

    ModuleLoader.prototype.define = function(moduleName, dModule) {
        if (moduleName in ModuleLoader.modules) throw new Error('Error, duplicate module');

        const module = ModuleLoader.modules[moduleName] = {}

        module.context = {
            __moduleName: moduleName,
            exports: {}
        }

        //Weak map with instance as the key, when the created instance is garbage collected or goes out of scope this will be cleaned up.
        module._private = {
            private_sections: new WeakMap(),
            instances: []
        };

        function private(action, instance) {
            switch (action) {
                case "create":
                    if (module._private.private_sections.has(instance)) throw new Error('Cannot create private store twice on the same instance! check calls to create.')
                    module._private.instances.push(instance);
                    module._private.private_sections.set(instance, {});
                    break;
                case "delete":
                    const index = module._private.instances.indexOf(instance);
                    if (index == -1) throw new Error('Invalid state');
                    module._private.instances.slice(index, 1);
                    return module._private.private_sections.delete(instance);
                    break;
                case "get":
                    return module._private.private_sections.get(instance);
                    break;
                default:
                    throw new Error('Invalid action');
                    break;
            }
        }

        dModule.call(module.context, private);
        ModuleLoader.modulesLoaded++;
    }

    ModuleLoader.prototype.remove = function(moduleName) {
        if (!moduleName in (ModuleLoader.modules)) return;

        /*
            Clean up as best we can.
        */
        const module = ModuleLoader.modules[moduleName];
        module.context.__moduleName = null;
        module.context.exports = null;
        module.cotext = null;
        module._private.instances.forEach(function(instance) { module._private.private_sections.delete(instance) });
        for (let i = 0; i < module._private.instances.length; i++) {
            module._private.instances[i] = undefined;
        }
        module._private.instances = undefined;
        module._private = null;
        delete ModuleLoader.modules[moduleName];
        ModuleLoader.modulesLoaded -= 1;
    }


    ModuleLoader.prototype.require = function(moduleName) {
        if (!(moduleName in ModuleLoader.modules)) throw new Error('Module does not exist');

        return ModuleLoader.modules[moduleName].context.exports;
    }



     return new ModuleLoader();
    })();

    loader.define('MyModule', function(private_store) {
        function MyClass() {
            //Creates the private storage facility. Called once in constructor.
            private_store("create", this);


            //Retrieve the private storage object from the storage facility.
            private_store("get", this).no = 1;
        }

        MyClass.prototype.incrementPrivateVar = function() {
            private_store("get", this).no += 1;
        }

        MyClass.prototype.getPrivateVar = function() {
            return private_store("get", this).no;
        }

        this.exports = MyClass;
    })

    //Get whatever is exported from MyModule
    const MyClass = loader.require('MyModule');

    //Create a new instance of `MyClass`
    const myClass = new MyClass();

    //Create another instance of `MyClass`
    const myClass2 = new MyClass();

    //print out current private vars
    console.log('pVar = ' + myClass.getPrivateVar())
    console.log('pVar2 = ' + myClass2.getPrivateVar())

    //Increment it
    myClass.incrementPrivateVar()

    //Print out to see if one affected the other or shared
    console.log('pVar after increment = ' + myClass.getPrivateVar())
    console.log('pVar after increment on other class = ' + myClass2.getPrivateVar())

    //Clean up.
    loader.remove('MyModule')

Fast query runs slow in SSRS

I Faced the same issue. For me it was just to unckeck the option :

Tablix Properties=> Page Break Option => Keep together on one page if possible

Of SSRS Report. It was trying to put all records on the same page instead of creating many pages.

How to make script execution wait until jquery is loaded

I'm not super fond of the interval thingies. When I want to defer jquery, or anything actually, it usually goes something like this.

Start with:

<html>
 <head>
  <script>var $d=[];var $=(n)=>{$d.push(n)}</script>
 </head>

Then:

 <body>
  <div id="thediv"></div>

  <script>
    $(function(){
       $('#thediv').html('thecode');
    });
  </script>

  <script src="http://code.jquery.com/jquery-3.2.1.min.js" type="text/javascript"></script>

Then finally:

  <script>for(var f in $d){$d[f]();}</script>
 </body>
<html>

Or the less mind-boggling version:

<script>var def=[];function defer(n){def.push(n)}</script>
<script>
defer(function(){
   $('#thediv').html('thecode');
});
</script>
<script src="http://code.jquery.com/jquery-3.2.1.min.js" type="text/javascript"></script>
<script>for(var f in def){def[f]();}</script>

And in the case of async you could execute the pushed functions on jquery onload.

<script async onload="for(var f in def){def[f]();}" 
src="jquery.min.js" type="text/javascript"></script>

Alternatively:

function loadscript(src, callback){
  var script = document.createElement('script');
  script.src = src
  script.async = true;
  script.onload = callback;
  document.body.appendChild(script);
};
loadscript("jquery.min", function(){for(var f in def){def[f]();}});

Access is denied when attaching a database

For those who could not fix the problem with the other solutions here, the following fix worked for me:

Go to your "DATA" folder in your SQL Server installation, right click, properties, security tab, and add full control permissions for the "NETWORK SERVICE" user.

http://decoding.wordpress.com/2008/08/25/sql-server-2005-expess-how-to-fix-error-3417/

(The above link is for SQL 2005, but this fixed a SQL 2008 R2 installation for me).

Some additional info: This problem showed up for me after replacing a secondary hard drive (which the SQL installation was on). I copied all the files, and restored the original drive letter to the new hard disk. However, the security permissions were not copied over. I think next time I will use a better method of copying data.

Use curly braces to initialize a Set in Python

Compare also the difference between {} and set() with a single word argument.

>>> a = set('aardvark')
>>> a
{'d', 'v', 'a', 'r', 'k'} 
>>> b = {'aardvark'}
>>> b
{'aardvark'}

but both a and b are sets of course.

Convert dataframe column to 1 or 0 for "true"/"false" values and assign to dataframe

Since you're dealing with values that are just supposed to be boolean anyway, just use == and convert the logical response to as.integer:

df <- data.frame(col = c("true", "true", "false"))
df
#     col
# 1  true
# 2  true
# 3 false
df$col <- as.integer(df$col == "true")
df
#   col
# 1   1
# 2   1
# 3   0

Subtract a value from every number in a list in Python?

To clarify an already posted solution due to questions in the comments

import numpy

array = numpy.array([49, 51, 53, 56])
array = array - 13

will output:

array([36, 38, 40, 43])

Redirect using AngularJS

Check your routing method:

if your routing state is like this

 .state('app.register', {
    url: '/register',
    views: {
      'menuContent': {
        templateUrl: 'templates/register.html',
      }
    }
  })

then you should use 

$location.path("/app/register");

Can't ignore UserInterfaceState.xcuserstate

All Answer is great but here is the one will remove for every user if you work in different Mac (Home and office)

git rm --cache */UserInterfaceState.xcuserstate
git commit -m "Never see you again, UserInterfaceState"

How to set selected value from Combobox?

In order to do the database style ComboBoxes manually trying to setup a relationship between a number (internal) and some text (visible), I've found you have to:

  1. Store you items in a list (You are close - except the string,string - need int,string)
  2. DataSource property to the list (You are good)
  3. DataMember,DataValue (You are good)
  4. Load default value (You are good)
  5. Put in value from database (Your question)
  6. Get value to put back in database (Your next question)

First things first. Change your KeyValuePair to so it looks like:

(0,"Select") (1,"Option 1")

Now, when you run your sql "Select empstatus from employees where blah" and get back an integer, you need to set the combobox without wasting a bunch of time.

Simply: *** SelectedVALUE - not Item ****

cmbEmployeeStatus.SelectedValue = 3;   //or

cmbEmployeeStatus.SelectedValue = intResultFromQuery;

This will work whether you have manually loaded the combobox with code values, as you did, or if you load the comboBox from a query.

If your foreign keys are integers, (which for what I do, they all are), life is easy. After the user makes the change to the comboBox, the value you will store in the database is SelectedValue. (Cast to int as needed.)

Here is my code to set the ComboBox to the value from the database:

if (t is DBInt) //Typical for ComboBox stuff
    {
    cb.SelectedValue = ((DBInt)t).value;
    }

And to retrieve:

((DBInt)t).value = (int) cb.SelectedValue;

DBInt is a wrapper for an Integer, but this is part of my ORM that gives me manual control over databinding, and reduces code errors.

Why did I answer this so late? I was struggling with this also, as there seems to be no good info on the web about how to do this. I figured it out, and thought I'd be nice and post it for someone else to see.

Draw horizontal rule in React Native

Maybe you should try using react-native-hr something like this:

<Hr lineColor='#b3b3b3'/>

documentation: https://www.npmjs.com/package/react-native-hr

Should __init__() call the parent class's __init__()?

If you need something from super's __init__ to be done in addition to what is being done in the current class's __init__, you must call it yourself, since that will not happen automatically. But if you don't need anything from super's __init__, no need to call it. Example:

>>> class C(object):
        def __init__(self):
            self.b = 1


>>> class D(C):
        def __init__(self):
            super().__init__() # in Python 2 use super(D, self).__init__()
            self.a = 1


>>> class E(C):
        def __init__(self):
            self.a = 1


>>> d = D()
>>> d.a
1
>>> d.b  # This works because of the call to super's init
1
>>> e = E()
>>> e.a
1
>>> e.b  # This is going to fail since nothing in E initializes b...
Traceback (most recent call last):
  File "<pyshell#70>", line 1, in <module>
    e.b  # This is going to fail since nothing in E initializes b...
AttributeError: 'E' object has no attribute 'b'

__del__ is the same way, (but be wary of relying on __del__ for finalization - consider doing it via the with statement instead).

I rarely use __new__. I do all the initialization in __init__.

Why extend the Android Application class?

You can access variables to any class without creating objects, if its extended by Application. They can be called globally and their state is maintained till application is not killed.

How to set Spinner Default by its Value instead of Position?

this is how i did it:

String[] listAges = getResources().getStringArray(R.array.ages);

        // Creating adapter for spinner
        ArrayAdapter<String> dataAdapter =
                new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, listAges);

        // Drop down layout style - list view with radio button
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        // attaching data adapter to spinner
        spinner_age.getBackground().setColorFilter(ContextCompat.getColor(this, R.color.spinner_icon), PorterDuff.Mode.SRC_ATOP);
        spinner_age.setAdapter(dataAdapter);
        spinner_age.setSelection(0);
        spinner_age.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String item = parent.getItemAtPosition(position).toString();

                if(position > 0){
                    // get spinner value
                    Toast.makeText(parent.getContext(), "Age..." + item, Toast.LENGTH_SHORT).show();
                }else{
                    // show toast select gender
                    Toast.makeText(parent.getContext(), "none" + item, Toast.LENGTH_SHORT).show();
                }
            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });

Is an HTTPS query string secure?

From a "sniff the network packet" point of view a GET request is safe, as the browser will first establish the secure connection and then send the request containing the GET parameters. But GET url's will be stored in the users browser history / autocomplete, which is not a good place to store e.g. password data in. Of course this only applies if you take the broader "Webservice" definition that might access the service from a browser, if you access it only from your custom application this should not be a problem.

So using post at least for password dialogs should be preferred. Also as pointed out in the link littlegeek posted a GET URL is more likely to be written to your server logs.

How to display an image from a path in asp.net MVC 4 and Razor view?

you can also try with this answer :

 <img src="~/Content/img/@Html.DisplayFor(model =>model.ImagePath)" style="height:200px;width:200px;"/>

A cron job for rails: best practices?

Assuming your tasks don't take too long to complete, just create a new controller with an action for each task. Implement the logic of the task as controller code, Then set up a cronjob at the OS level that uses wget to invoke the URL of this controller and action at the appropriate time intervals. The advantages of this method are you:

  1. Have full access to all your Rails objects just as in a normal controller.
  2. Can develop and test just as you do normal actions.
  3. Can also invoke your tasks adhoc from a simple web page.
  4. Don't consume any more memory by firing up additional ruby/rails processes.

Downloading a picture via urllib and python

I have found this answer and I edit that in more reliable way

def download_photo(self, img_url, filename):
    try:
        image_on_web = urllib.urlopen(img_url)
        if image_on_web.headers.maintype == 'image':
            buf = image_on_web.read()
            path = os.getcwd() + DOWNLOADED_IMAGE_PATH
            file_path = "%s%s" % (path, filename)
            downloaded_image = file(file_path, "wb")
            downloaded_image.write(buf)
            downloaded_image.close()
            image_on_web.close()
        else:
            return False    
    except:
        return False
    return True

From this you never get any other resources or exceptions while downloading.

Set background image according to screen resolution

Put into css file:

html { background: url(images/bg.jpg) no-repeat center center fixed; -webkit-background-size: cover; -moz-background-size: cover; -o-background-size: cover; background-size: cover; }

URL images/bg.jpg is your background image

Why are only final variables accessible in anonymous class?

Try this code,

Create Array List and put value inside that and return it :

private ArrayList f(Button b, final int a)
{
    final ArrayList al = new ArrayList();
    b.addClickHandler(new ClickHandler() {

         @Override
        public void onClick(ClickEvent event) {
             int b = a*5;
             al.add(b);
        }
    });
    return al;
}

Stop a youtube video with jquery?

if you have autoplay property in the iframe src it wont help to reload the src attr/prop so you have to replace the autoplay=1 to autoplay=0

  var stopVideo = function(player) {
    var vidSrc = player.prop('src').replace('autoplay=1','autoplay=0');
    player.prop('src', vidSrc);
  };

  stopVideo($('#video'));

Using the "With Clause" SQL Server 2008

There are two types of WITH clauses:

Here is the FizzBuzz in SQL form, using a WITH common table expression (CTE).

;WITH mil AS (
 SELECT TOP 1000000 ROW_NUMBER() OVER ( ORDER BY c.column_id ) [n]
 FROM master.sys.all_columns as c
 CROSS JOIN master.sys.all_columns as c2
)                
 SELECT CASE WHEN n  % 3 = 0 THEN
             CASE WHEN n  % 5 = 0 THEN 'FizzBuzz' ELSE 'Fizz' END
        WHEN n % 5 = 0 THEN 'Buzz'
        ELSE CAST(n AS char(6))
     END + CHAR(13)
 FROM mil

Here is a select statement also using a WITH clause

SELECT * FROM orders WITH (NOLOCK) where order_id = 123

Combining Two Images with OpenCV

The three best way to do it using a single line of code

import cv2
import numpy as np 


img = cv2.imread('Imgs/Saint_Roch_new/data/Point_4_Face.jpg')
dim = (256, 256)
resizedLena = cv2.resize(img, dim, interpolation = cv2.INTER_LINEAR)
X, Y = resizedLena, resizedLena

# Methode 1: Using Numpy (hstack, vstack)
Fusion_Horizontal = np.hstack((resizedLena, Y, X))
Fusion_Vertical   = np.vstack((newIMG, X))

cv2.imshow('Fusion_Vertical using vstack', Fusion_Vertical)
cv2.waitKey(0)

# Methode 2: Using Numpy (contanate)
Fusion_Vertical   = np.concatenate((resizedLena, X, Y), axis=0)
Fusion_Horizontal = np.concatenate((resizedLena, X, Y), axis=1)

cv2.imshow("Fusion_Horizontal usung concatenate", Fusion_Horizontal)
cv2.waitKey(0)


# Methode 3: Using OpenCV (vconcat, hconcat)
Fusion_Vertical   = cv2.vconcat([resizedLena, X, Y])
Fusion_Horizontal = cv2.hconcat([resizedLena, X, Y])

cv2.imshow("Fusion_Horizontal Using hconcat", Fusion_Horizontal)
cv2.waitKey(0)

C# 30 Days From Todays Date

You need to store the first run time of the program in order to do this. How I'd probably do it is using the built in application settings in visual studio. Make one called InstallDate which is a User Setting and defaults to DateTime.MinValue or something like that (e.g. 1/1/1900).

Then when the program is run the check is simple:

if (appmode == "trial")
{
  // If the FirstRunDate is MinValue, it's the first run, so set this value up
  if (Properties.Settings.Default.FirstRunDate == DateTime.MinValue)
  {
    Properties.Settings.Default.FirstRunDate = DateTime.Now;
    Properties.Settings.Default.Save(); 
  }

  // Now check whether 30 days have passed since the first run date
  if (Properties.Settings.Default.FirstRunDate.AddMonths(1) < DateTime.Now)
  {
    // Do whatever you want to do on expiry (exception message/shut down/etc.)
  }
}

User settings are stored in a pretty weird location (something like C:\Documents and Settings\YourName\Local Settings\Application Data) so it will be pretty hard for average joe to find it anyway. If you want to be paranoid, just encrypt the date before saving it to settings.

EDIT: Sigh, misread the question, not as complex as I thought >.>

Concatenating bits in VHDL

Here is an example of concatenation operator:

architecture EXAMPLE of CONCATENATION is
   signal Z_BUS : bit_vector (3 downto 0);
   signal A_BIT, B_BIT, C_BIT, D_BIT : bit;
begin
   Z_BUS <= A_BIT & B_BIT & C_BIT & D_BIT;
end EXAMPLE;

How to write Unicode characters to the console?

It's likely that your output encoding is set to ASCII. Try using this before sending output:

Console.OutputEncoding = System.Text.Encoding.UTF8;

(MSDN link to supporting documentation.)

And here's a little console test app you may find handy:

C#

using System;
using System.Text;

public static class ConsoleOutputTest {
    public static void Main() {
        Console.OutputEncoding = System.Text.Encoding.UTF8;
        for (var i = 0; i <= 1000; i++) {
            Console.Write(Strings.ChrW(i));
            if (i % 50 == 0) { // break every 50 chars
                Console.WriteLine();
            }
        }
        Console.ReadKey();
    }
}

VB.NET

imports Microsoft.VisualBasic
imports System

public module ConsoleOutputTest 
    Sub Main()
        Console.OutputEncoding = System.Text.Encoding.UTF8
        dim i as integer
        for i = 0 to 1000
            Console.Write(ChrW(i))
            if i mod 50 = 0 'break every 50 chars 
                Console.WriteLine()
            end if
        next
    Console.ReadKey()
    End Sub
end module

It's also possible that your choice of Console font does not support that particular character. Click on the Windows Tool-bar Menu (icon like C:.) and select Properties -> Font. Try some other fonts to see if they display your character properly:

picture of console font edit

Android LinearLayout : Add border with shadow around a LinearLayout

As an alternative, you might use a 9 patch image as the background for your layout, allowing for more "natural" shadows:

enter image description here

Result:

enter image description here

Put the image in your /res/drawable folder.
Make sure the file extension is .9.png, not .png

By the way, this is a modified (reduced to the minimum square size) of an existing resource found in the API 19 sdk resources folder.
I left the red markers, since they don't seem to be harmful, as shown in the draw9patch tool.

[EDIT]

About 9 patches, in case you never had anything to do with them.

Simply add it as the background of your View.

The black-marked areas (left and top) will stretch (vertically, horizontally).
The black-marked areas (right, bottom) define the "content area" (where it's possible to add text or Views - you can call the unmarked regions "padding", if you like to).

Tutorial: http://radleymarx.com/blog/simple-guide-to-9-patch/

Angular pass callback function to child component as @Input similar to AngularJS way

An alternative to the answer SnareChops gave.

You can use .bind(this) in your template to have the same effect. It may not be as clean but it saves a couple of lines. I'm currently on angular 2.4.0

@Component({
  ...
  template: '<child [myCallback]="theCallback.bind(this)"></child>',
  directives: [ChildComponent]
})
export class ParentComponent {

  public theCallback(){
    ...
  }
}

@Component({...})
export class ChildComponent{
  //This will be bound to the ParentComponent.theCallback
  @Input()
  public myCallback: Function; 
  ...
}

Where to put a textfile I want to use in eclipse?

Just create a folder Files under src and put your file there. This will look like src/Files/myFile.txt

Note: In your code you need to specify like this Files/myFile.txt e.g.

getResource("Files/myFile.txt");

So when you build your project and run the .jar file this should be able to work.

Why am I getting an error "Object literal may only specify known properties"?

As of TypeScript 1.6, properties in object literals that do not have a corresponding property in the type they're being assigned to are flagged as errors.

Usually this error means you have a bug (typically a typo) in your code, or in the definition file. The right fix in this case would be to fix the typo. In the question, the property callbackOnLoactionHash is incorrect and should have been callbackOnLocationHash (note the mis-spelling of "Location").

This change also required some updates in definition files, so you should get the latest version of the .d.ts for any libraries you're using.

Example:

interface TextOptions {
    alignment?: string;
    color?: string;
    padding?: number;
}
function drawText(opts: TextOptions) { ... }
drawText({ align: 'center' }); // Error, no property 'align' in 'TextOptions'

But I meant to do that

There are a few cases where you may have intended to have extra properties in your object. Depending on what you're doing, there are several appropriate fixes

Type-checking only some properties

Sometimes you want to make sure a few things are present and of the correct type, but intend to have extra properties for whatever reason. Type assertions (<T>v or v as T) do not check for extra properties, so you can use them in place of a type annotation:

interface Options {
    x?: string;
    y?: number;
}

// Error, no property 'z' in 'Options'
let q1: Options = { x: 'foo', y: 32, z: 100 };
// OK
let q2 = { x: 'foo', y: 32, z: 100 } as Options;
// Still an error (good):
let q3 = { x: 100, y: 32, z: 100 } as Options;

These properties and maybe more

Some APIs take an object and dynamically iterate over its keys, but have 'special' keys that need to be of a certain type. Adding a string indexer to the type will disable extra property checking

Before

interface Model {
  name: string;
}
function createModel(x: Model) { ... }

// Error
createModel({name: 'hello', length: 100});

After

interface Model {
  name: string;
  [others: string]: any;
}
function createModel(x: Model) { ... }

// OK
createModel({name: 'hello', length: 100});

This is a dog or a cat or a horse, not sure yet

interface Animal { move; }
interface Dog extends Animal { woof; }
interface Cat extends Animal { meow; }
interface Horse extends Animal { neigh; }

let x: Animal;
if(...) {
  x = { move: 'doggy paddle', woof: 'bark' };
} else if(...) {
  x = { move: 'catwalk', meow: 'mrar' };
} else {
  x = { move: 'gallop', neigh: 'wilbur' };
}

Two good solutions come to mind here

Specify a closed set for x

// Removes all errors
let x: Dog|Cat|Horse;

or Type assert each thing

// For each initialization
  x = { move: 'doggy paddle', woof: 'bark' } as Dog;

This type is sometimes open and sometimes not

A clean solution to the "data model" problem using intersection types:

interface DataModelOptions {
  name?: string;
  id?: number;
}
interface UserProperties {
  [key: string]: any;
}
function createDataModel(model: DataModelOptions & UserProperties) {
 /* ... */
}
// findDataModel can only look up by name or id
function findDataModel(model: DataModelOptions) {
 /* ... */
}
// OK
createDataModel({name: 'my model', favoriteAnimal: 'cat' });
// Error, 'ID' is not correct (should be 'id')
findDataModel({ ID: 32 });

See also https://github.com/Microsoft/TypeScript/issues/3755

What is the difference between Serializable and Externalizable in Java?

Object Serialization uses the Serializable and Externalizable interfaces. A Java object is only serializable. if a class or any of its superclasses implements either the java.io.Serializable interface or its subinterface, java.io.Externalizable. Most of the java class are serializable.

  • NotSerializableException: packageName.ClassName « To participate a Class Object in serialization process, The class must implement either Serializable or Externalizable interface.

enter image description here

Serializable Interface

Object Serialization produces a stream with information about the Java classes for the objects which are being saved. For serializable objects, sufficient information is kept to restore those objects even if a different (but compatible) version of the implementation of the class is present. The Serializable interface is defined to identify classes which implement the serializable protocol:

package java.io;

public interface Serializable {};
  • The serialization interface has no methods or fields and serves only to identify the semantics of being serializable. For serializing/deserializing a class, either we can use default writeObject and readObject methods (or) we can overriding writeObject and readObject methods from a class.
  • JVM will have complete control in serializing the object. use transient keyword to prevent the data member from being serialized.
  • Here serializable objects is reconstructed directly from the stream without executing
  • InvalidClassException « In deserialization process, if local class serialVersionUID value is different from the corresponding sender's class. then result's in conflict as java.io.InvalidClassException: com.github.objects.User; local class incompatible: stream classdesc serialVersionUID = 5081877, local class serialVersionUID = 50818771
  • The values of the non-transient and non-static fields of the class get serialized.

Externalizable Interface

For Externalizable objects, only the identity of the class of the object is saved by the container; the class must save and restore the contents. The Externalizable interface is defined as follows:

package java.io;

public interface Externalizable extends Serializable
{
    public void writeExternal(ObjectOutput out)
        throws IOException;

    public void readExternal(ObjectInput in)
        throws IOException, java.lang.ClassNotFoundException;
}
  • The Externalizable interface has two methods, an externalizable object must implement a writeExternal and readExternal methods to save/restore the state of an object.
  • Programmer has to take care of which objects to be serialized. As a programmer take care of Serialization So, here transient keyword will not restrict any object in Serialization process.
  • When an Externalizable object is reconstructed, an instance is created using the public no-arg constructor, then the readExternal method called. Serializable objects are restored by reading them from an ObjectInputStream.

  • OptionalDataException « The fields MUST BE IN THE SAME ORDER AND TYPE as we wrote them out. If there is any mismatch of type from the stream it throws OptionalDataException.

    @Override public void writeExternal(ObjectOutput out) throws IOException {
    out.writeInt( id );
    out.writeUTF( role );
    out.writeObject(address);
}
@Override public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
    this.id = in.readInt();
    this.address = (Address) in.readObject();
    this.role = in.readUTF();
}

  • The instance fields of the class which written (exposed) to ObjectOutput get serialized.

Example « implements Serializable

class Role {
    String role;
}
class User extends Role implements Serializable {

    private static final long serialVersionUID = 5081877L;
    Integer id;
    Address address;

    public User() {
        System.out.println("Default Constructor get executed.");
    }
    public User( String role ) {
        this.role = role;
        System.out.println("Parametarised Constructor.");
    }
}

class Address implements Serializable {

    private static final long serialVersionUID = 5081877L;
    String country;
}

Example « implements Externalizable

class User extends Role implements Externalizable {

    Integer id;
    Address address;
    // mandatory public no-arg constructor
    public User() {
        System.out.println("Default Constructor get executed.");
    }
    public User( String role ) {
        this.role = role;
        System.out.println("Parametarised Constructor.");
    }

    @Override
    public void writeExternal(ObjectOutput out) throws IOException {
        out.writeInt( id );
        out.writeUTF( role );
        out.writeObject(address);
    }
    @Override
    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        this.id = in.readInt();
        this.address = (Address) in.readObject();
        this.role = in.readUTF();
    }
}

Example

public class CustomClass_Serialization {
    static String serFilename = "D:/serializable_CustomClass.ser";

    public static void main(String[] args) throws IOException {
        Address add = new Address();
        add.country = "IND";

        User obj = new User("SE");
        obj.id = 7;
        obj.address = add;

        // Serialization
        objects_serialize(obj, serFilename);
        objects_deserialize(obj, serFilename);

        // Externalization
        objects_WriteRead_External(obj, serFilename);
    }

    public static void objects_serialize( User obj, String serFilename ) throws IOException{
        FileOutputStream fos = new FileOutputStream( new File( serFilename ) );
        ObjectOutputStream objectOut = new ObjectOutputStream( fos );

        // java.io.NotSerializableException: com.github.objects.Address
        objectOut.writeObject( obj );
        objectOut.flush();
        objectOut.close();
        fos.close();

        System.out.println("Data Stored in to a file");
    }
    public static void objects_deserialize( User obj, String serFilename ) throws IOException{
        try {
            FileInputStream fis = new FileInputStream( new File( serFilename ) );
            ObjectInputStream ois = new ObjectInputStream( fis );
            Object readObject;
            readObject = ois.readObject();
            String calssName = readObject.getClass().getName();
            System.out.println("Restoring Class Name : "+ calssName); // InvalidClassException

            User user = (User) readObject;
            System.out.format("Obj[Id:%d, Role:%s] \n", user.id, user.role);

            Address add = (Address) user.address;
            System.out.println("Inner Obj : "+ add.country );
            ois.close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    public static void objects_WriteRead_External( User obj, String serFilename ) throws IOException {
        FileOutputStream fos = new FileOutputStream(new File( serFilename ));
        ObjectOutputStream objectOut = new ObjectOutputStream( fos );

        obj.writeExternal( objectOut );
        objectOut.flush();

        fos.close();

        System.out.println("Data Stored in to a file");

        try {
            // create a new instance and read the assign the contents from stream.
            User user = new User();

            FileInputStream fis = new FileInputStream(new File( serFilename ));
            ObjectInputStream ois = new ObjectInputStream( fis );

            user.readExternal(ois);

            System.out.format("Obj[Id:%d, Role:%s] \n", user.id, user.role);

            Address add = (Address) user.address;
            System.out.println("Inner Obj : "+ add.country );
            ois.close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}

@see

How to emit an event from parent to child?

In a parent component you can use @ViewChild() to access child component's method/variable.

@Component({
  selector: 'app-number-parent',
  templateUrl: './number-parent.component.html'
})
export class NumberParentComponent {
    @ViewChild(NumberComponent)
    private numberComponent: NumberComponent;
    increase() {
       this.numberComponent.increaseByOne();
    }
    decrease() {
       this.numberComponent.decreaseByOne();
    }
}

Update:

Angular 8 onwards - 

@ViewChild(NumberComponent, { static: false })

How to get the result of OnPostExecute() to main activity because AsyncTask is a separate class?

You can call the get() method of AsyncTask (or the overloaded get(long, TimeUnit)). This method will block until the AsyncTask has completed its work, at which point it will return you the Result.

It would be wise to be doing other work between the creation/start of your async task and calling the get method, otherwise you aren't utilizing the async task very efficiently.

Using multiple .cpp files in c++ program?

In C/C++ you have header files (*.H). There you declare your functions/classes. So for example you will have to #include "second.h" to your main.cpp file.

In second.h you just declare like this void yourFunction(); In second.cpp you implement it like 

void yourFunction() { 
   doSomethng(); 
}

Don't forget to #include "second.h" also in the beginning of second.cpp

Hope this helps:)

Cross-platform way of getting temp directory in Python

The simplest way, based on @nosklo's comment and answer:

import tempfile
tmp = tempfile.mkdtemp()

But if you want to manually control the creation of the directories:

import os
from tempfile import gettempdir
tmp = os.path.join(gettempdir(), '.{}'.format(hash(os.times())))
os.makedirs(tmp)

That way you can easily clean up after yourself when you are done (for privacy, resources, security, whatever) with:

from shutil import rmtree
rmtree(tmp, ignore_errors=True)

This is similar to what applications like Google Chrome and Linux systemd do. They just use a shorter hex hash and an app-specific prefix to "advertise" their presence.

Python causing: IOError: [Errno 28] No space left on device: '../results/32766.html' on disk with lots of space

It turns out the best solution for me here was to just reformat the drive. Once reformatted all these problems were no longer problems.

How to get 0-padded binary representation of an integer in java?

I would write my own util class with the method like below

public class NumberFormatUtils {

public static String longToBinString(long val) {
    char[] buffer = new char[64];
    Arrays.fill(buffer, '0');
    for (int i = 0; i < 64; ++i) {
        long mask = 1L << i;
        if ((val & mask) == mask) {
            buffer[63 - i] = '1';
        }
    }
    return new String(buffer);
}

public static void main(String... args) {
    long value = 0b0000000000000000000000000000000000000000000000000000000000000101L;
    System.out.println(value);
    System.out.println(Long.toBinaryString(value));
    System.out.println(NumberFormatUtils.longToBinString(value));
}

}

Output:

5
101
0000000000000000000000000000000000000000000000000000000000000101

The same approach could be applied to any integral types. Pay attention to the type of mask

long mask = 1L << i;

Can't connect to HTTPS site using cURL. Returns 0 length content instead. What can I do?

The best way to use https and avoid security issues is to use Firefox (or another tool) and download the certificate to your server. This webpage helped me a lot, and these were the steps that worked for me:

1) Open in Firefox the URL you're gonna use with CURL

2) On the address bar click on the padlock > more information (FF versions can have different menus, just find it). Click the View certificate button > Details tab.

3) Highlight the "right" certificate in Certificate hierarchy. In my case it was the second of three, called "cPanel, Inc. Certification Authority". I just discovered the right one by "trial and error" method.

4) Click the Export button. In my case the one who worked was the file type "PEM with chains" (again by trial and error method).

5) Then in your PHP script add:

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);    
curl_setopt($ch, CURLOPT_CAINFO, [PATH_TO_CRT_FILE]);

In addition I'd say that we must pay attention on the fact that these steps will probably need to be redone once a year or whenever the URL certificate is replaced or renewed.

How can you represent inheritance in a database?

@Bill Karwin describes three inheritance models in his SQL Antipatterns book, when proposing solutions to the SQL Entity-Attribute-Value antipattern. This is a brief overview:

Single Table Inheritance (aka Table Per Hierarchy Inheritance):

Using a single table as in your first option is probably the simplest design. As you mentioned, many attributes that are subtype-specific will have to be given a NULL value on rows where these attributes do not apply. With this model, you would have one policies table, which would look something like this:

+------+---------------------+----------+----------------+------------------+
| id   | date_issued         | type     | vehicle_reg_no | property_address |
+------+---------------------+----------+----------------+------------------+
|    1 | 2010-08-20 12:00:00 | MOTOR    | 01-A-04004     | NULL             |
|    2 | 2010-08-20 13:00:00 | MOTOR    | 02-B-01010     | NULL             |
|    3 | 2010-08-20 14:00:00 | PROPERTY | NULL           | Oxford Street    |
|    4 | 2010-08-20 15:00:00 | MOTOR    | 03-C-02020     | NULL             |
+------+---------------------+----------+----------------+------------------+

\------ COMMON FIELDS -------/          \----- SUBTYPE SPECIFIC FIELDS -----/

Keeping the design simple is a plus, but the main problems with this approach are the following:

  • When it comes to adding new subtypes, you would have to alter the table to accommodate the attributes that describe these new objects. This can quickly become problematic when you have many subtypes, or if you plan to add subtypes on a regular basis.

  • The database will not be able to enforce which attributes apply and which don't, since there is no metadata to define which attributes belong to which subtypes.

  • You also cannot enforce NOT NULL on attributes of a subtype that should be mandatory. You would have to handle this in your application, which in general is not ideal.

Concrete Table Inheritance:

Another approach to tackle inheritance is to create a new table for each subtype, repeating all the common attributes in each table. For example:

--// Table: policies_motor
+------+---------------------+----------------+
| id   | date_issued         | vehicle_reg_no |
+------+---------------------+----------------+
|    1 | 2010-08-20 12:00:00 | 01-A-04004     |
|    2 | 2010-08-20 13:00:00 | 02-B-01010     |
|    3 | 2010-08-20 15:00:00 | 03-C-02020     |
+------+---------------------+----------------+
                          
--// Table: policies_property    
+------+---------------------+------------------+
| id   | date_issued         | property_address |
+------+---------------------+------------------+
|    1 | 2010-08-20 14:00:00 | Oxford Street    |   
+------+---------------------+------------------+

This design will basically solve the problems identified for the single table method:

  • Mandatory attributes can now be enforced with NOT NULL.

  • Adding a new subtype requires adding a new table instead of adding columns to an existing one.

  • There is also no risk that an inappropriate attribute is set for a particular subtype, such as the vehicle_reg_no field for a property policy.

  • There is no need for the type attribute as in the single table method. The type is now defined by the metadata: the table name.

However this model also comes with a few disadvantages:

  • The common attributes are mixed with the subtype specific attributes, and there is no easy way to identify them. The database will not know either.

  • When defining the tables, you would have to repeat the common attributes for each subtype table. That's definitely not DRY.

  • Searching for all the policies regardless of the subtype becomes difficult, and would require a bunch of UNIONs.

This is how you would have to query all the policies regardless of the type:

SELECT     date_issued, other_common_fields, 'MOTOR' AS type
FROM       policies_motor
UNION ALL
SELECT     date_issued, other_common_fields, 'PROPERTY' AS type
FROM       policies_property;

Note how adding new subtypes would require the above query to be modified with an additional UNION ALL for each subtype. This can easily lead to bugs in your application if this operation is forgotten.

Class Table Inheritance (aka Table Per Type Inheritance):

This is the solution that @David mentions in the other answer. You create a single table for your base class, which includes all the common attributes. Then you would create specific tables for each subtype, whose primary key also serves as a foreign key to the base table. Example:

CREATE TABLE policies (
   policy_id          int,
   date_issued        datetime,

   -- // other common attributes ...
);

CREATE TABLE policy_motor (
    policy_id         int,
    vehicle_reg_no    varchar(20),

   -- // other attributes specific to motor insurance ...

   FOREIGN KEY (policy_id) REFERENCES policies (policy_id)
);

CREATE TABLE policy_property (
    policy_id         int,
    property_address  varchar(20),

   -- // other attributes specific to property insurance ...

   FOREIGN KEY (policy_id) REFERENCES policies (policy_id)
);

This solution solves the problems identified in the other two designs:

  • Mandatory attributes can be enforced with NOT NULL.

  • Adding a new subtype requires adding a new table instead of adding columns to an existing one.

  • No risk that an inappropriate attribute is set for a particular subtype.

  • No need for the type attribute.

  • Now the common attributes are not mixed with the subtype specific attributes anymore.

  • We can stay DRY, finally. There is no need to repeat the common attributes for each subtype table when creating the tables.

  • Managing an auto incrementing id for the policies becomes easier, because this can be handled by the base table, instead of each subtype table generating them independently.

  • Searching for all the policies regardless of the subtype now becomes very easy: No UNIONs needed - just a SELECT * FROM policies.

I consider the class table approach as the most suitable in most situations.

The names of these three models come from Martin Fowler's book Patterns of Enterprise Application Architecture.

difference between css height : 100% vs height : auto

A height of 100% for is, presumably, the height of your browser's inner window, because that is the height of its parent, the page. An auto height will be the minimum height of necessary to contain .

How to put scroll bar only for modal-body?

In your modal body you have to set a height, it can be % vh or calc:

modal-body {
    height: 80vh;
    overflow-x: auto;
}

or

modal-body {
    height: calc(100vh - 5em);
    overflow-x: auto;
}

In my case look like: enter image description here

Checking if a folder exists using a .bat file

I think the answer is here (possibly duplicate):

How to test if a file is a directory in a batch script?

IF EXIST %VAR%\NUL ECHO It's a directory

Replace %VAR% with your directory. Please read the original answer because includes details about handling white spaces in the folder name.

As foxidrive said, this might not be reliable on NT class windows. It works for me, but I know it has some limitations (which you can find in the referenced question)

if exist "c:\folder\" echo folder exists

should be enough for modern windows.

Equivalent of explode() to work with strings in MySQL

First of all you should change database structure - the score in this case is some kind of composite value and should be stored in two columns, eg. score_host, score_guest.

MySQL doesn't provide explode() equivalent however in this case you could use SUBSTRING() and LOCATE() to cut off score of a host and a guest.

SELECT 
   CONVERT(SUBSTRING(score, 1, LOCATE('-',score) - 2) USING INTEGER) as score_host,
   CONVERT(SUBSTRING(score, LOCATE('-',score)+2) USING INTEGER) as score_guest
FROM ...;

CONVERT() is used to cast a string "23" into number 23.

java.sql.SQLException: Incorrect string value: '\xF0\x9F\x91\xBD\xF0\x9F...'

Append the line useUnicode=true&amp;characterEncoding=UTF-8 to your jdbc url.

In your case the data is not being send using UTF-8 encoding.

sql query to get earliest date

 
SELECT TOP 1 ID, Name, Score, [Date]
FROM myTable
WHERE ID = 2
Order BY [Date]

Why does the 'int' object is not callable error occur when using the sum() function?

This means that somewhere else in your code, you have something like:

sum = 0

Which shadows the builtin sum (which is callable) with an int (which isn't).

Convert Dictionary<string,string> to semicolon separated string in c#

 
using System.Linq;

string s = string.Join(";", myDict.Select(x => x.Key + "=" + x.Value).ToArray());

(And if you're using .NET 4, or newer, then you can omit the final ToArray call.)

How to import component into another root component in Angular 2

Angular RC5 & RC6

If you are getting the above mentioned error in your Jasmine tests, it is most likely because you have to declare the unrenderable component in your TestBed.configureTestingModule({}).

The TestBed configures and initializes an environment for unit testing and provides methods for mocking/creating/injecting components and services in unit tests.

If you don't declare the component before your unit tests are executed, Angular will not know what <courses></courses> is in your template file.

Here is an example:

import {async, ComponentFixture, TestBed} from "@angular/core/testing";
import {AppComponent} from "../app.component";
import {CoursesComponent} from './courses.component';

describe('CoursesComponent', () => {
  let component: CoursesComponent;
  let fixture: ComponentFixture<CoursesComponent>;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [
        AppComponent,
        CoursesComponent
      ],
      imports: [
        BrowserModule
        // If you have any other imports add them here
      ]
    })
    .compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(CoursesComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should create', () => {
    expect(component).toBeTruthy();
  });
});

How can I count the occurrences of a list item?

If you only want one item's count, use the count method:

>>> [1, 2, 3, 4, 1, 4, 1].count(1)
3

Don't use this if you want to count multiple items. Calling count in a loop requires a separate pass over the list for every count call, which can be catastrophic for performance. If you want to count all items, or even just multiple items, use Counter, as explained in the other answers.

Is it possible to change the radio button icon in an android radio button group

The easier way to only change the radio button is simply set selector for drawable right

<RadioButton
    ...
    android:button="@null"
    android:checked="false"
    android:drawableRight="@drawable/radio_button_selector" />

And the selector is:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/ic_checkbox_checked" android:state_checked="true" />
    <item android:drawable="@drawable/ic_checkbox_unchecked" android:state_checked="false" /></selector>

That's all

Call multiple functions onClick ReactJS

Calling multiple functions on onClick for any element, you can create a wrapper function, something like this.

wrapperFunction = () => {
    //do something
    function 1();
    //do something
    function 2();
    //do something
    function 3();
}

These functions can be defined as a method on the parent class and then called from the wrapper function.

You may have the main element which will cause the onChange like this,

<a href='#' onClick={this.wrapperFunction}>Some Link</a>

Java String.split() Regex

Can you invert your regex so split by the non operation characters?

String ops[] = string.split("[a-z]")
// ops == [+, -, *, /, <, >, >=, <=, == ]

This obviously doesn't return the variables in the array. Maybe you can interleave two splits (one by the operators, one by the variables)

Remove all the children DOM elements in div

In Dojo 1.7 or newer, use domConstruct.empty(String|DomNode):

require(["dojo/dom-construct"], function(domConstruct){
  // Empty node's children byId:
  domConstruct.empty("someId");
});

In older Dojo, use dojo.empty(String|DomNode) (deprecated at Dojo 1.8):

dojo.empty( id or DOM node );

Each of these empty methods safely removes all children of the node.

Inner join of DataTables in C#

If you are allowed to use LINQ, take a look at the following example. It creates two DataTables with integer columns, fills them with some records, join them using LINQ query and outputs them to Console.

    DataTable dt1 = new DataTable();
    dt1.Columns.Add("CustID", typeof(int));
    dt1.Columns.Add("ColX", typeof(int));
    dt1.Columns.Add("ColY", typeof(int));

    DataTable dt2 = new DataTable();
    dt2.Columns.Add("CustID", typeof(int));
    dt2.Columns.Add("ColZ", typeof(int));

    for (int i = 1; i <= 5; i++)
    {
        DataRow row = dt1.NewRow();
        row["CustID"] = i;
        row["ColX"] = 10 + i;
        row["ColY"] = 20 + i;
        dt1.Rows.Add(row);

        row = dt2.NewRow();
        row["CustID"] = i;
        row["ColZ"] = 30 + i;
        dt2.Rows.Add(row);
    }

    var results = from table1 in dt1.AsEnumerable()
                 join table2 in dt2.AsEnumerable() on (int)table1["CustID"] equals (int)table2["CustID"]
                 select new
                 {
                     CustID = (int)table1["CustID"],
                     ColX = (int)table1["ColX"],
                     ColY = (int)table1["ColY"],
                     ColZ = (int)table2["ColZ"]
                 };
    foreach (var item in results)
    {
        Console.WriteLine(String.Format("ID = {0}, ColX = {1}, ColY = {2}, ColZ = {3}", item.CustID, item.ColX, item.ColY, item.ColZ));
    }
    Console.ReadLine();

// Output:
// ID = 1, ColX = 11, ColY = 21, ColZ = 31
// ID = 2, ColX = 12, ColY = 22, ColZ = 32
// ID = 3, ColX = 13, ColY = 23, ColZ = 33
// ID = 4, ColX = 14, ColY = 24, ColZ = 34
// ID = 5, ColX = 15, ColY = 25, ColZ = 35

HikariCP - connection is not available

I managed to fix it finally. The problem is not related to HikariCP. The problem persisted because of some complex methods in REST controllers executing multiple changes in DB through JPA repositories. For some reasons calls to these interfaces resulted in a growing number of "freezed" active connections, exhausting the pool. Either annotating these methods as @Transactional or enveloping all the logic in a single call to transactional service method seem to solve the problem.

Installation of SQL Server Business Intelligence Development Studio

If you have installed SQL 2005 express edition and want to install BIDS (Business Intelligence Development Studio) then go to here Microsoft SQL Server 2005 Express Edition Toolkit

This has an option to install BIDS on my machine, and is the only way l could get hold of BIDS for SQL Server 2005 express edition.

Also this package l think has also allowed me to install both BIDS 2005 & 2008 express edition on the same machine.

How can I reverse the order of lines in a file?

 
$ (tac 2> /dev/null || tail -r)

Try tac, which works on Linux, and if that doesn't work use tail -r, which works on BSD and OSX.

How to truncate the time on a DateTime object in Python?

See more at https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Series.dt.floor.html

It's now 2019, I think the most efficient way to do it is:

df['truncate_date'] = df['timestamp'].dt.floor('d')

Can't find bundle for base name /Bundle, locale en_US

I had the same problem using Netbeans. I went to the project folder and copied the properties file. I think clicked "build" and then "classes." I added the properties file in that folder. That solved my problem.

Is it possible to sort a ES6 map object?

The snippet below sorts given map by its keys and maps the keys to key-value objects again. I used localeCompare function since my map was string->string object map.

var hash = {'x': 'xx', 't': 'tt', 'y': 'yy'};
Object.keys(hash).sort((a, b) => a.localeCompare(b)).map(function (i) {
            var o = {};
            o[i] = hash[i];
            return o;
        });

result: [{t:'tt'}, {x:'xx'}, {y: 'yy'}];

Can git undo a checkout of unstaged files

I just had that happen to me, I checked out an entire folder containing hours of work! Fortunately I found out that my IDE Netbeans keeps an history of each file, that allowed me to recuperate 99% of the stuff even though I needed to fix a few things manually.

What is the Swift equivalent of isEqualToString in Objective-C?

One important point is that Swift's == on strings might not be equivalent to Objective-C's -isEqualToString:. The peculiarity lies in differences in how strings are represented between Swift and Objective-C.

Just look on this example:

let composed = "Ö" // U+00D6 LATIN CAPITAL LETTER O WITH DIAERESIS
let decomposed = composed.decomposedStringWithCanonicalMapping // (U+004F LATIN CAPITAL LETTER O) + (U+0308 COMBINING DIAERESIS)

composed.utf16.count // 1
decomposed.utf16.count // 2

let composedNSString = composed as NSString
let decomposedNSString = decomposed as NSString

decomposed == composed // true, Strings are equal
decomposedNSString == composedNSString // false, NSStrings are not

NSString's are represented as a sequence of UTF–16 code units (roughly read as an array of UTF-16 (fixed-width) code units). Whereas Swift Strings are conceptually sequences of "Characters", where "Character" is something that abstracts extended grapheme cluster (read Character = any amount of Unicode code points, usually something that the user sees as a character and text input cursor jumps around).

The next thing to mention is Unicode. There is a lot to write about it, but here we are interested in something called "canonical equivalence". Using Unicode code points, visually the same "character" can be encoded in more than one way. For example, "Á" can be represented as a precomposed "Á" or as decomposed A + ?´ (that's why in example composed.utf16 and decomposed.utf16 had different lengths). A good thing to read on that is this great article.

-[NSString isEqualToString:], according to the documentation, compares NSStrings code unit by code unit, so:

[Á] != [A, ?´]

Swift's String == compares characters by canonical equivalence.

[ [Á] ] == [ [A, ?´] ]

In swift the above example will return true for Strings. That's why -[NSString isEqualToString:] is not equivalent to Swift's String ==. Equivalent pure Swift comparison could be done by comparing String's UTF-16 Views:

decomposed.utf16.elementsEqual(composed.utf16) // false, UTF-16 code units are not the same
decomposedNSString == composedNSString // false, UTF-16 code units are not the same
decomposedNSString.isEqual(to: composedNSString as String) // false, UTF-16 code units are not the same

Also, there is a difference between NSString == NSString and String == String in Swift. The NSString == will cause isEqual and UTF-16 code unit by code unit comparison, where as String == will use canonical equivalence:

decomposed == composed // true, Strings are equal
decomposed as NSString == composed as NSString // false, UTF-16 code units are not the same

And the whole example:

let composed = "Ö" // U+00D6 LATIN CAPITAL LETTER O WITH DIAERESIS
let decomposed = composed.decomposedStringWithCanonicalMapping // (U+004F LATIN CAPITAL LETTER O) + (U+0308 COMBINING DIAERESIS)

composed.utf16.count // 1
decomposed.utf16.count // 2

let composedNSString = composed as NSString
let decomposedNSString = decomposed as NSString

decomposed == composed // true, Strings are equal
decomposedNSString == composedNSString // false, NSStrings are not

decomposed.utf16.elementsEqual(composed.utf16) // false, UTF-16 code units are not the same
decomposedNSString == composedNSString // false, UTF-16 code units are not the same
decomposedNSString.isEqual(to: composedNSString as String) // false, UTF-16 code units are not the same

Enter key pressed event handler

For those who struggle at capturing Enter key on TextBox or other input control, if your Form has AcceptButton defined, you will not be able to use KeyDown event to capture Enter.

What you should do is to catch the Enter key at form level. Add this code to the form:

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
    if ((this.ActiveControl == myTextBox) && (keyData == Keys.Return))
    {
        //do something
        return true;
    }
    else
    {
        return base.ProcessCmdKey(ref msg, keyData);
    }
}

How to remove leading and trailing spaces from a string

You Can Use

string txt = "                   i am a string                                    ";
txt = txt.TrimStart().TrimEnd();

Output is "i am a string"

can't load package: package .: no buildable Go source files

If you want all packages in that repository, use ... to signify that, like:

go get code.google.com/p/go.text/...

How can I zoom an HTML element in Firefox and Opera?

Zoom and transform scale are not the same thing. They are applied at different times. Zoom is applied before the rendering happens, transform - after. The result of this is if you take a div with width/height = 100% nested inside of another div, with fixed size, if you apply zoom, everything inside your inner zoom will shrink, or grow, but if you apply transform your entire inner div will shrink (even though width/height is set to 100%, they are not going to be 100% after transformation).

Two Page Login with Spring Security 3.2.x

There should be three pages here:

  1. Initial login page with a form that asks for your username, but not your password.
  2. You didn't mention this one, but I'd check whether the client computer is recognized, and if not, then challenge the user with either a CAPTCHA or else a security question. Otherwise the phishing site can simply use the tendered username to query the real site for the security image, which defeats the purpose of having a security image. (A security question is probably better here since with a CAPTCHA the attacker could have humans sitting there answering the CAPTCHAs to get at the security images. Depends how paranoid you want to be.)
  3. A page after that that displays the security image and asks for the password.

I don't see this short, linear flow being sufficiently complex to warrant using Spring Web Flow.

I would just use straight Spring Web MVC for steps 1 and 2. I wouldn't use Spring Security for the initial login form, because Spring Security's login form expects a password and a login processing URL. Similarly, Spring Security doesn't provide special support for CAPTCHAs or security questions, so you can just use Spring Web MVC once again.

You can handle step 3 using Spring Security, since now you have a username and a password. The form login page should display the security image, and it should include the user-provided username as a hidden form field to make Spring Security happy when the user submits the login form. The only way to get to step 3 is to have a successful POST submission on step 1 (and 2 if applicable).

How can I rename a project folder from within Visual Studio?

TFS users: If you are using source control that requires you to warn it before your rename files/folders then look at this answer instead which covers the extra steps required.

To rename a project's folder, file (.*proj) and display name in Visual Studio:

  • Close the solution.
  • Rename the folder(s) outside Visual Studio. (Rename in TFS if using source control)
  • Open the solution, ignoring the warnings (answer "no" if asked to load a project from source control).
  • Go through all the unavailable projects and...
    • Open the properties window for the project (highlight the project and press Alt+Enter or F4, or right-click > properties).
    • Set the property 'File Path' to the new location.
      • If the property is not editable (as in Visual Studio 2012), then open the .sln file directly in another editor such as Notepad++ and update the paths there instead. (You may need to check-out the solution first in TFS, etc.)
    • Reload the project - right-click > reload project.
    • Change the display name of the project, by highlighting it and pressing F2, or right-click > rename.

Note: Other suggested solutions that involve removing and then re-adding the project to the solution will break project references.

If you perform these steps then you might also consider renaming the following to match:

  1. Assembly
  2. Default/Root Namespace
  3. Namespace of existing files (use the refactor tools in Visual Studio or ReSharper's inconsistent namespaces tool)

Also consider modifying the values of the following assembly attributes:

  1. AssemblyProductAttribute
  2. AssemblyDescriptionAttribute
  3. AssemblyTitleAttribute

macro - open all files in a folder

You have to add this line just before loop

    MyFile = Dir
Loop

Device not detected in Eclipse when connected with USB cable

Go to http://developer.android.com/tools/extras/oem-usb.html#InstallingDriver and follow the steps on the android website but on browsing for the USB folder don't use the directory specified -> ((sdk)\extras\google\usb_driver). (sdk) just means your sdk location.

Your phone should have the correct driver and it can be accessed when you plug it in and go to the CD Driver in My Computer, in my case it's G:\drivers\adb_driver. Use this directory instead and it should work. (It may be differ with devices).

How do I get the first n characters of a string without checking the size or going out of bounds?

Use the substring method, as follows:

int n = 8;
String s = "Hello, World!";
System.out.println(s.substring(0,n);

If n is greater than the length of the string, this will throw an exception, as one commenter has pointed out. one simple solution is to wrap all this in the condition if(s.length()<n) in your else clause, you can choose whether you just want to print/return the whole String or handle it another way.

What is a pre-revprop-change hook in SVN, and how do I create it?

For Linux to allow the edition of a log comment,

  • locate the file pre-revprop-change.tmpl in the hooks directory of your repository
  • copy the file to the same directory, renaming it to pre-revprop-change
  • give execute permission to the file (for the server user, e.g. www-data)

Edited: (thanks to lindes)

  • after that you might have to edit the script to return an exit value of 0 for the kind of edits, that you want to allow.

Trim a string based on the string length

There is a Apache Commons StringUtils function which does this.

s = StringUtils.left(s, 10)

If len characters are not available, or the String is null, the String will be returned without an exception. An empty String is returned if len is negative.

StringUtils.left(null, ) = null
StringUtils.left(, -ve) = ""
StringUtils.left("", *) = ""
StringUtils.left("abc", 0) = ""
StringUtils.left("abc", 2) = "ab"
StringUtils.left("abc", 4) = "abc"

StringUtils.Left JavaDocs

Courtesy:Steeve McCauley

Add a new element to an array without specifying the index in Bash

As Dumb Guy points out, it's important to note whether the array starts at zero and is sequential. Since you can make assignments to and unset non-contiguous indices ${#array[@]} is not always the next item at the end of the array.

$ array=(a b c d e f g h)
$ array[42]="i"
$ unset array[2]
$ unset array[3]
$ declare -p array     # dump the array so we can see what it contains
declare -a array='([0]="a" [1]="b" [4]="e" [5]="f" [6]="g" [7]="h" [42]="i")'
$ echo ${#array[@]}
7
$ echo ${array[${#array[@]}]}
h

Here's how to get the last index:

$ end=(${!array[@]})   # put all the indices in an array
$ end=${end[@]: -1}    # get the last one
$ echo $end
42

That illustrates how to get the last element of an array. You'll often see this:

$ echo ${array[${#array[@]} - 1]}
g

As you can see, because we're dealing with a sparse array, this isn't the last element. This works on both sparse and contiguous arrays, though:

$ echo ${array[@]: -1}
i

LD_LIBRARY_PATH vs LIBRARY_PATH

Since I link with gcc why ld is being called, as the error message suggests?

gcc calls ld internally when it is in linking mode.

java.lang.NoClassDefFoundError: org/hamcrest/SelfDescribing

"java.lang.SecurityException: class" org.hamcrest.Matchers "'s signer information does not match signer information of other classes in the same package"

Do it: Right-click on your package click on Build Path -> Configure Build Path Click on the Libraries tab Remove JUnit Apply and close Ready.

Remove duplicated rows

Remove duplicate rows of a dataframe

library(dplyr)
mydata <- mtcars

# Remove duplicate rows of the dataframe
distinct(mydata)

In this dataset, there is not a single duplicate row so it returned same number of rows as in mydata.



Remove Duplicate Rows based on a one variable

library(dplyr)
mydata <- mtcars

# Remove duplicate rows of the dataframe using carb variable
distinct(mydata,carb, .keep_all= TRUE)

The .keep_all function is used to retain all other variables in the output data frame.



Remove Duplicate Rows based on multiple variables

library(dplyr)
mydata <- mtcars

# Remove duplicate rows of the dataframe using cyl and vs variables
distinct(mydata, cyl,vs, .keep_all= TRUE)

The .keep_all function is used to retain all other variables in the output data frame.

(from: http://www.datasciencemadesimple.com/remove-duplicate-rows-r-using-dplyr-distinct-function/ )

hasOwnProperty in JavaScript

hasOwnProperty expects the property name as a string, so it would be shape1.hasOwnProperty("name")

Merging arrays with the same keys

Two entries in an array can't share a key, you'll need to change the key for the duplicate

Are there any free Xml Diff/Merge tools available?

I use TortoiseMerge, which is included in TortoiseSVN program

And we have talked about File Diff tools in this thread, not dedicated to XML though

https://stackoverflow.com/questions/1830962/file-differencing-software-on-windows

How do I set up a private Git repository on GitHub? Is it even possible?

On January 7th 2019, GitHub announced free and unlimited private repositories for all GitHub users, paying or not. When creating a new repository, you can simply select the Private option.

Run on server option not appearing in Eclipse

Did you create a Web Project? If you right click on the project and go to Properties > Project Facets is Dynamic Web Module selected?

Exception: Unexpected end of ZLIB input stream

You have to call close() on the GZIPOutputStream before you attempt to read it. The final bytes of the file will only be written when the file is actually closed. (This is irrespective of any explicit buffering in the output stack. The stream only knows to compress and write the last bytes when you tell it to close. A flush() probably won't help ... though calling finish() instead of close() should work. Look at the javadocs.)

Here's the correct code (in Java);

package test;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

public class GZipTest {

    public static void main(String[] args) throws
                FileNotFoundException, IOException {
        String name = "/tmp/test";
        GZIPOutputStream gz = new GZIPOutputStream(new FileOutputStream(name));
        gz.write(10);
        gz.close();       // Remove this to reproduce the reported bug
        System.out.println(new GZIPInputStream(new FileInputStream(name)).read());
    }
}

(I've not implemented resource management or exception handling / reporting properly as they are not relevant to the purpose of this code. Don't treat this as an example of "good code".)

How can I compile my Perl script so it can be executed on systems without perl installed?

  1. Install PAR::Packer. Example for *nix:

    sudo cpan -i PAR::Packer

    For Strawberry Perl for Windows or for ActivePerl and MSVC installed:

    cpan -i PAR::Packer

  2. Pack it with pp. It will create an executable named "example" or "example.exe" on Windows.

    pp -o example example.pl

This would work only on the OS where it was built.

P.S. It is really hard to find a Unix clone without Perl. Did you mean Windows?

How to get 'System.Web.Http, Version=5.2.3.0?

I did Install-Package Microsoft.AspNet.WebApi.Core -version 5.2.3 but it still did not work. Then looked in my project bin folder and saw that it still had the old System.Web.Mvc file.

So I manually copied the newer file from the package to the bin folder. Then I was up and running again.

what is the use of annotations @Id and @GeneratedValue(strategy = GenerationType.IDENTITY)? Why the generationtype is identity?

In a Object Relational Mapping context, every object needs to have a unique identifier. You use the @Id annotation to specify the primary key of an entity.

The @GeneratedValue annotation is used to specify how the primary key should be generated. In your example you are using an Identity strategy which

Indicates that the persistence provider must assign primary keys for the entity using a database identity column.

There are other strategies, you can see more here.

How can I replace non-printable Unicode characters in Java?

I have used this simple function for this:

private static Pattern pattern = Pattern.compile("[^ -~]");
private static String cleanTheText(String text) {
    Matcher matcher = pattern.matcher(text);
    if ( matcher.find() ) {
        text = text.replace(matcher.group(0), "");
    }
    return text;
}

Hope this is useful.

Get domain name

If you want specific users to have access to all or part of the WMI object space, you need to permission them as shown here. Note that you have to be running on as an admin to perform this setting.

Remove all elements contained in another array

Proper way to remove all elements contained in another array is to make source array same object by remove only elements:

Array.prototype.removeContained = function(array) {
  var i, results;
  i = this.length;
  results = [];
  while (i--) {
    if (array.indexOf(this[i]) !== -1) {
      results.push(this.splice(i, 1));
    }
  }
  return results;
};

Or CoffeeScript equivalent:

Array.prototype.removeContained = (array) ->
  i = @length
  @splice i, 1 while i-- when array.indexOf(@[i]) isnt -1

Testing inside chrome dev tools:

19:33:04.447 a=1
19:33:06.354 b=2
19:33:07.615 c=3
19:33:09.981 arr = [a,b,c]
19:33:16.460 arr1 = arr

19:33:20.317 arr1 === arr
19:33:20.331 true

19:33:43.592 arr.removeContained([a,c])
19:33:52.433 arr === arr1
19:33:52.438 true

Using Angular framework is the best way to keep pointer to source object when you update collections without large amount of watchers and reloads.

Read a plain text file with php

$your_variable = file_get_contents("file_to_read.txt");

How to get the current time as datetime

if you just need the hour of the day

let calendar = NSCalendar.currentCalendar()
var hour = calendar.component(.Hour,fromDate: NSDate())

Import pfx file into particular certificate store from command line

In newer version of windows the Certuil has [CertificateStoreName] where we can give the store name. In earlier version windows this was not possible.

Installing *.pfx certificate: certutil -f -p "" -enterprise -importpfx root ""

Installing *.cer certificate: certutil -addstore -enterprise -f -v root ""

For more details below command can be executed in windows cmd. C:>certutil -importpfx -? Usage: CertUtil [Options] -importPFX [CertificateStoreName] PFXFile [Modifiers]

How can I concatenate a string and a number in Python?

If it worked the way you expected it to (resulting in "abc9"), what would "9" + 9 deliver? 18 or "99"?

To remove this ambiguity, you are required to make explicit what you want to convert in this case:

"abc" + str(9)

Search an array for matching attribute

 
let restaurant = restaurants.find(element => element.restaurant.food == "chicken");

The find() method returns the value of the first element in the provided array that satisfies the provided testing function.

in: https://developer.mozilla.org/pt-PT/docs/Web/JavaScript/Reference/Global_Objects/Array/find

Angularjs $http post file and form data

I had similar problem when had to upload file and send user token info at the same time. transformRequest along with forming FormData helped:

        $http({
            method: 'POST',
            url: '/upload-file',
            headers: {
                'Content-Type': 'multipart/form-data'
            },
            data: {
                email: Utils.getUserInfo().email,
                token: Utils.getUserInfo().token,
                upload: $scope.file
            },
            transformRequest: function (data, headersGetter) {
                var formData = new FormData();
                angular.forEach(data, function (value, key) {
                    formData.append(key, value);
                });

                var headers = headersGetter();
                delete headers['Content-Type'];

                return formData;
            }
        })
        .success(function (data) {

        })
        .error(function (data, status) {

        });

For getting file $scope.file I used custom directive:

app.directive('file', function () {
    return {
        scope: {
            file: '='
        },
        link: function (scope, el, attrs) {
            el.bind('change', function (event) {
                var file = event.target.files[0];
                scope.file = file ? file : undefined;
                scope.$apply();
            });
        }
    };
});

Html:

<input type="file" file="file" required />

Is there a way to force npm to generate package-lock.json?

As several answer explained the you should run:

npm i

BUT if it does not solve...

Check the version of your npm executable. (For me it was 3.x.x which doesn't uses the package-lock.json (at all))

npm -v

It should be at least 5.x.x (which introduced the package-lock.json file.)

To update npm on Linux, follow these instructions.

For more details about package files, please read this medium story.

How to parse XML and count instances of a particular node attribute?

XML:

<foo>
   <bar>
      <type foobar="1"/>
      <type foobar="2"/>
   </bar>
</foo>

Python code:

import xml.etree.cElementTree as ET

tree = ET.parse("foo.xml")
root = tree.getroot() 
root_tag = root.tag
print(root_tag) 

for form in root.findall("./bar/type"):
    x=(form.attrib)
    z=list(x)
    for i in z:
        print(x[i])

Output:

foo
1
2

Why can't I shrink a transaction log file, even after backup?

'sp_removedbreplication' didn't solve the issue for me as SQL just returned saying that the Database wasn't part of a replication...

I found my answer here:

Basically I had to create a replication, reset all of the replication pointers to Zero; then delete the replication I had just made. i.e.

Execute SP_ReplicationDbOption {DBName},Publish,true,1
GO
Execute sp_repldone @xactid = NULL, @xact_segno = NULL, @numtrans = 0, @time = 0, @reset = 1
GO
DBCC ShrinkFile({LogFileName},0)
GO
Execute SP_ReplicationDbOption {DBName},Publish,false,1
GO

Multiple ping script in Python

 
import subprocess,os,threading,time
from queue import Queue
lock=threading.Lock()
_start=time.time()
def check(n):
    with open(os.devnull, "wb") as limbo:
                ip="192.168.21.{0}".format(n)
                result=subprocess.Popen(["ping", "-n", "1", "-w", "300", ip],stdout=limbo, stderr=limbo).wait()
                with lock:                    
                    if not result:
                        print (ip, "active")                    
                    else:
                        pass                        

def threader():
    while True:
        worker=q.get()
        check(worker)
        q.task_done()
q=Queue()

for x in range(255):
    t=threading.Thread(target=threader)
    t.daemon=True
    t.start()
for worker in range(1,255):
    q.put(worker)
q.join()
print("Process completed in: ",time.time()-_start)

I think this will be better one.

HTML/CSS Making a textbox with text that is grayed out, and disappears when I click to enter info, how?

Here's a one-liner slim way for layering text on top of an input in jQuery using ES6 syntax.

_x000D_
_x000D_ 
$('.input-group > input').focus(e => $(e.currentTarget).parent().find('.placeholder').hide()).blur(e => { if (!$(e.currentTarget).val()) $(e.currentTarget).parent().find('.placeholder').show(); });
_x000D_ 
* {
  font-family: sans-serif;
}

.input-group {
  position: relative;
}

.input-group > input {
  width: 150px;
  padding: 10px 0px 10px 25px;
}

.input-group > .placeholder {
  position: absolute;
  top: 50%;
  left: 25px;
  transform: translateY(-50%);
  color: #929292;
}
_x000D_ 
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="input-group">
  <span class="placeholder">Username</span>
  <input>
</div>
_x000D_
_x000D_
_x000D_

Can PHP cURL retrieve response headers AND body in a single request?

Here is my contribution to the debate ... This returns a single array with the data separated and the headers listed. This works on the basis that CURL will return a headers chunk [ blank line ] data

curl_setopt($ch, CURLOPT_HEADER, 1); // we need this to get headers back
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_VERBOSE, true);

// $output contains the output string
$output = curl_exec($ch);

$lines = explode("\n",$output);

$out = array();
$headers = true;

foreach ($lines as $l){
    $l = trim($l);

    if ($headers && !empty($l)){
        if (strpos($l,'HTTP') !== false){
            $p = explode(' ',$l);
            $out['Headers']['Status'] = trim($p[1]);
        } else {
            $p = explode(':',$l);
            $out['Headers'][$p[0]] = trim($p[1]);
        }
    } elseif (!empty($l)) {
        $out['Data'] = $l;
    }

    if (empty($l)){
        $headers = false;
    }
}

Excel formula to remove space between words in a cell

It is SUBSTITUTE(B1," ",""), not REPLACE(xx;xx;xx).

Is there a bash command which counts files?

Lots of answers here, but some don't take into account

  • file names with spaces, newlines, or control characters in them
  • file names that start with hyphens (imagine a file called -l)
  • hidden files, that start with a dot (if the glob was *.log instead of log*
  • directories that match the glob (e.g. a directory called logs that matches log*)
  • empty directories (i.e. the result is 0)
  • extremely large directories (listing them all could exhaust memory)

Here's a solution that handles all of them:

ls 2>/dev/null -Ubad1 -- log* | wc -l

Explanation:

  • -U causes ls to not sort the entries, meaning it doesn't need to load the entire directory listing in memory
  • -b prints C-style escapes for nongraphic characters, crucially causing newlines to be printed as \n.
  • -a prints out all files, even hidden files (not strictly needed when the glob log* implies no hidden files)
  • -d prints out directories without attempting to list the contents of the directory, which is what ls normally would do
  • -1 makes sure that it's on one column (ls does this automatically when writing to a pipe, so it's not strictly necessary)
  • 2>/dev/null redirects stderr so that if there are 0 log files, ignore the error message. (Note that shopt -s nullglob would cause ls to list the entire working directory instead.)
  • wc -l consumes the directory listing as it's being generated, so the output of ls is never in memory at any point in time.
  • -- File names are separated from the command using -- so as not to be understood as arguments to ls (in case log* is removed)

The shell will expand log* to the full list of files, which may exhaust memory if it's a lot of files, so then running it through grep is be better:

ls -Uba1 | grep ^log | wc -l

This last one handles extremely large directories of files without using a lot of memory (albeit it does use a subshell). The -d is no longer necessary, because it's only listing the contents of the current directory.