Programs & Examples On #Param

0

How Exactly Does @param Work - Java

@param will not affect testNumber.It is a Javadoc comment - i.e used for generating documentation . You can put a Javadoc comment immediately before a class, field, method, constructor, or interface such as @param, @return . Generally begins with '@' and must be the first thing on the line.

The Advantage of using @param is :- By creating simple Java classes that contain attributes and some custom Javadoc tags, you allow those classes to serve as a simple metadata description for code generation.

    /* 
       *@param testNumber
       *@return integer
    */
    public int main testNumberIsValid(int testNumber){

       if (testNumber < 6) {
          //Something
        }
     }

Whenever in your code if you reuse testNumberIsValid method, IDE will show you the parameters the method accepts and return type of the method.

TypeScript and array reduce function

With TypeScript generics you can do something like this.

class Person {
    constructor (public Name : string, public Age: number) {}
}

var list = new Array<Person>();
list.push(new Person("Baby", 1));
list.push(new Person("Toddler", 2));
list.push(new Person("Teen", 14));
list.push(new Person("Adult", 25));

var oldest_person = list.reduce( (a, b) => a.Age > b.Age ? a : b );
alert(oldest_person.Name);

Function passed as template argument

The reason your functor example does not work is that you need an instance to invoke the operator().

ios simulator: how to close an app

I had a difficult time in finding a way in XCode 7.2, but finally I had found one. First press Shift+Command+ H twice. This will open up all the apps that are currently open.

Swipe left/right to the app you actually want to close. Just Swipe Up using the Touchpad while Holding the App would close the app.

How to install multiple python packages at once using pip

pip install -r requirements.txt

and in the requirements.txt file you put your modules in a list, with one item per line.

  • Django=1.3.1

  • South>=0.7

  • django-debug-toolbar

Python3: ImportError: No module named '_ctypes' when using Value from module multiprocessing

Installing libffi-dev and re-installing python3.7 fixed the problem for me.

to cleanly build py 3.7 libffi-dev is required or else later stuff will fail

If using RHEL/Fedora:

yum install libffi-devel

or

sudo dnf install libffi-devel

If using Debian/Ubuntu:

sudo apt-get install libffi-dev

Adding VirtualHost fails: Access Forbidden Error 403 (XAMPP) (Windows 7)

For many it's a permission issue, but for me it turns out the error was brought about by a mistake in the form I was trying to submit. To be specific i had accidentally put a "greater than" sign after the value of "action". So I would suggest you take a second look at your code.

How do I cancel form submission in submit button onclick event?

<input type='button' onclick='buttonClick()' />

<script>
function buttonClick(){
    //Validate Here
    document.getElementsByTagName('form')[0].submit();
}
</script>

git add remote branch

You can check if you got your remote setup right and have the proper permissions with

git ls-remote origin

if you called your remote "origin". If you get an error you probably don't have your security set up correctly such as uploading your public key to github for example. If things are setup correctly, you will get a list of the remote references. Now

git fetch origin

will work barring any other issues like an unplugged network cable.

Once you have that done, you can get any branch you want that the above command listed with

git checkout some-branch

this will create a local branch of the same name as the remote branch and check it out.

MySQL 1062 - Duplicate entry '0' for key 'PRIMARY'

You need to specify the primary key as auto-increment

CREATE TABLE `momento_distribution`
  (
     `momento_id`       INT(11) NOT NULL AUTO_INCREMENT,
     `momento_idmember` INT(11) NOT NULL,
     `created_at`       DATETIME DEFAULT NULL,
     `updated_at`       DATETIME DEFAULT NULL,
     `unread`           TINYINT(1) DEFAULT '1',
     `accepted`         VARCHAR(10) NOT NULL DEFAULT 'pending',
     `ext_member`       VARCHAR(255) DEFAULT NULL,
     PRIMARY KEY (`momento_id`, `momento_idmember`),
     KEY `momento_distribution_FI_2` (`momento_idmember`),
     KEY `accepted` (`accepted`, `ext_member`)
  )
ENGINE=InnoDB
DEFAULT CHARSET=latin1$$

With regards to comment below, how about:

ALTER TABLE `momento_distribution`
  CHANGE COLUMN `id` `id` INT(11) NOT NULL AUTO_INCREMENT,
  DROP PRIMARY KEY,
  ADD PRIMARY KEY (`id`);

A PRIMARY KEY is a unique index, so if it contains duplicates, you cannot assign the column to be unique index, so you may need to create a new column altogether

How to run a JAR file

Java

class Hello{
   public static void main(String [] args){
    System.out.println("Hello Shahid");
   }
}

manifest.mf

Manifest-version: 1.0
Main-Class: Hello

On command Line:

$ jar cfm HelloMss.jar  manifest.mf Hello.class 
$ java -jar HelloMss.jar

Output:

Hello Shahid

How to set up file permissions for Laravel?

The permissions for the storage and vendor folders should stay at 775, for obvious security reasons.

However, both your computer and your server Apache need to be able to write in these folders. Ex: when you run commands like php artisan, your computer needs to write in the logs file in storage.

All you need to do is to give ownership of the folders to Apache :

sudo chown -R www-data:www-data /path/to/your/project/vendor
sudo chown -R www-data:www-data /path/to/your/project/storage

Then you need to add your computer (referenced by it's username) to the group to which the server Apache belongs. Like so :

sudo usermod -a -G www-data userName

NOTE: Most frequently, groupName is www-data but in your case, replace it with _www

Angular2 multiple router-outlet in the same template

There seems to be another (rather hacky) way to reuse the router-outlet in one template. This answer is intendend for informational purposes only and the techniques used here should probably not be used in production.

https://stackblitz.com/edit/router-outlet-twice-with-events

The router-outlet is wrapped by an ng-template. The template is updated by listening to events of the router. On every event the template is swapped and re-swapped with an empty placeholder. Without this "swapping" the template would not be updated.

This most definetly is not a recommended approach though, since the whole swapping of two templates seems a bit hacky.

in the controller:

  ngOnInit() {
    this.router.events.subscribe((routerEvent: Event) => {
      console.log(routerEvent);
      this.myTemplateRef = this.trigger;
      setTimeout(() => {
        this.myTemplateRef = this.template;
      }, 0);
    });
  }

in the template:

<div class="would-be-visible-on-mobile-only">
  This would be the mobile-layout with a router-outlet (inside a template): 
  <br>
  <ng-container *ngTemplateOutlet="myTemplateRef"></ng-container>
</div>

<hr>

<div class="would-be-visible-on-desktop-only">
  This would be the desktop-layout with a router-outlet (inside a template): 
  <br>
  <ng-container *ngTemplateOutlet="myTemplateRef"></ng-container>
</div>

<ng-template #template>
    <br>
    This is my counter: {{counter}}
    inside the template, the router-outlet should follow
    <router-outlet>
    </router-outlet>
</ng-template>

<ng-template #trigger>
  template to trigger changes...
</ng-template>

Failed to load JavaHL Library

i tried every single solution available and finally for me the problem was:

uninstall Native JavaHL 1.6

install everything under Subclipse from this site:

http://subclipse.tigris.org/update_1.10.x>

Using set_facts and with_items together in Ansible

Updated 2018-06-08: My previous answer was a bit of hack so I have come back and looked at this again. This is a cleaner Jinja2 approach.

- name: Set fact 4
  set_fact:
    foo: "{% for i in foo_result.results %}{% do foo.append(i) %}{% endfor %}{{ foo }}"

I am adding this answer as current best answer for Ansible 2.2+ does not completely cover the original question. Thanks to Russ Huguley for your answer this got me headed in the right direction but it left me with a concatenated string not a list. This solution gets a list but becomes even more hacky. I hope this gets resolved in a cleaner manner.

- name: build foo_string
  set_fact:
    foo_string: "{% for i in foo_result.results %}{{ i.ansible_facts.foo_item }}{% if not loop.last %},{% endif %}{%endfor%}"

- name: set fact foo
  set_fact:
    foo: "{{ foo_string.split(',') }}"

Is there a printf converter to print in binary format?

void print_ulong_bin(const unsigned long * const var, int bits) {
        int i;

        #if defined(__LP64__) || defined(_LP64)
                if( (bits > 64) || (bits <= 0) )
        #else
                if( (bits > 32) || (bits <= 0) )
        #endif
                return;

        for(i = 0; i < bits; i++) { 
                printf("%lu", (*var >> (bits - 1 - i)) & 0x01);
        }
}

should work - untested.

Combine hover and click functions (jQuery)?

var hoverAndClick = function() {
    // Your actions here
} ;

$("#target").hover( hoverAndClick ).click( hoverAndClick ) ;

How to set downloading file name in ASP.NET Web API

If you are using ASP.NET Core MVC, the answers above are ever so slightly altered...

In my action method (which returns async Task<JsonResult>) I add the line (anywhere before the return statement):

Response.Headers.Add("Content-Disposition", $"attachment; filename={myFileName}");

Spring 5.0.3 RequestRejectedException: The request was rejected because the URL was not normalized

I encountered the same problem with:

Spring Boot version = 1.5.10
Spring Security version = 4.2.4


The problem occurred on the endpoints, where the ModelAndView viewName was defined with a preceding forward slash. Example:

ModelAndView mav = new ModelAndView("/your-view-here");

If I removed the slash it worked fine. Example:

ModelAndView mav = new ModelAndView("your-view-here");

I also did some tests with RedirectView and it seemed to work with a preceding forward slash.

Java Compare Two Lists

EDIT

Here are two versions. One using ArrayList and other using HashSet

Compare them and create your own version from this, until you get what you need.

This should be enough to cover the:

P.S: It is not a school assignment :) So if you just guide me it will be enough

part of your question.

continuing with the original answer:

You may use a java.util.Collection and/or java.util.ArrayList for that.

The retainAll method does the following:

Retains only the elements in this collection that are contained in the specified collection

see this sample:

import java.util.Collection;
import java.util.ArrayList;
import java.util.Arrays;

public class Repeated {
    public static void main( String  [] args ) {
        Collection listOne = new ArrayList(Arrays.asList("milan","dingo", "elpha", "hafil", "meat", "iga", "neeta.peeta"));
        Collection listTwo = new ArrayList(Arrays.asList("hafil", "iga", "binga", "mike", "dingo"));

        listOne.retainAll( listTwo );
        System.out.println( listOne );
    }
}

EDIT

For the second part ( similar values ) you may use the removeAll method:

Removes all of this collection's elements that are also contained in the specified collection.

This second version gives you also the similar values and handles repeated ( by discarding them).

This time the Collection could be a Set instead of a List ( the difference is, the Set doesn't allow repeated values )

import java.util.Collection;
import java.util.HashSet;
import java.util.Arrays;

class Repeated {
      public static void main( String  [] args ) {

          Collection<String> listOne = Arrays.asList("milan","iga",
                                                    "dingo","iga",
                                                    "elpha","iga",
                                                    "hafil","iga",
                                                    "meat","iga", 
                                                    "neeta.peeta","iga");

          Collection<String> listTwo = Arrays.asList("hafil",
                                                     "iga",
                                                     "binga", 
                                                     "mike", 
                                                     "dingo","dingo","dingo");

          Collection<String> similar = new HashSet<String>( listOne );
          Collection<String> different = new HashSet<String>();
          different.addAll( listOne );
          different.addAll( listTwo );

          similar.retainAll( listTwo );
          different.removeAll( similar );

          System.out.printf("One:%s%nTwo:%s%nSimilar:%s%nDifferent:%s%n", listOne, listTwo, similar, different);
      }
}

Output:

$ java Repeated
One:[milan, iga, dingo, iga, elpha, iga, hafil, iga, meat, iga, neeta.peeta, iga]

Two:[hafil, iga, binga, mike, dingo, dingo, dingo]

Similar:[dingo, iga, hafil]

Different:[mike, binga, milan, meat, elpha, neeta.peeta]

If it doesn't do exactly what you need, it gives you a good start so you can handle from here.

Question for the reader: How would you include all the repeated values?

Any way to break if statement in PHP?

i have a simple solution without lot of changes. the initial statement is

I want to break the if statement above and stop executing echo "yes"; or such codes which are no longer necessary to be executed, there may be or may not be an additional condition, is there way to do this?

so, it seem simple. try code like this.

$a="test";
if("test"==$a)
{
  if (1==0){
      echo "yes"; // this line while never be executed. 
      // and can be reexecuted simply by changing if (1==0) to if (1==1) 
  }
}
echo "finish";

if you want to try without this code, it's simple. and you can back when you want. another solution is comment blocks. or simply thinking and try in another separated code and copy paste only the result in your final code. and if a code is no longer nescessary, in your case, the result can be

$a="test";
echo "finish";

with this code, the original statement is completely respected.. :) and more readable!

Close window automatically after printing dialog closes

The following solution is working for IE9, IE8, Chrome, and FF newer versions as of 2014-03-10. The scenario is this: you are in a window (A), where you click a button/link to launch the printing process, then a new window (B) with the contents to be printed is opened, the printing dialog is shown immediately, and you can either cancel or print, and then the new window (B) closes automatically.

The following code allows this. This javascript code is to be placed in the html for window A (not for window B):

/**
 * Opens a new window for the given URL, to print its contents. Then closes the window.
 */
function openPrintWindow(url, name, specs) {
  var printWindow = window.open(url, name, specs);
    var printAndClose = function() {
        if (printWindow.document.readyState == 'complete') {
            clearInterval(sched);
            printWindow.print();
            printWindow.close();
        }
    }
    var sched = setInterval(printAndClose, 200);
};

The button/link to launch the process has simply to invoke this function, as in:

openPrintWindow('http://www.google.com', 'windowTitle', 'width=820,height=600');

Converting Object to JSON and JSON to Object in PHP, (library like Gson for Java)

for more extendability for large scale apps use oop style with encapsulated fields.

Simple way :-

  class Fruit implements JsonSerializable {

        private $type = 'Apple', $lastEaten = null;

        public function __construct() {
            $this->lastEaten = new DateTime();
        }

        public function jsonSerialize() {
            return [
                'category' => $this->type,
                'EatenTime' => $this->lastEaten->format(DateTime::ISO8601)
            ];
        }
    }

echo json_encode(new Fruit()); //which outputs:

{"category":"Apple","EatenTime":"2013-01-31T11:17:07-0500"}

Real Gson on PHP :-

  1. http://jmsyst.com/libs/serializer
  2. http://symfony.com/doc/current/components/serializer.html
  3. http://framework.zend.com/manual/current/en/modules/zend.serializer.html
  4. http://fractal.thephpleague.com/ - serialize only

concatenate two database columns into one resultset column

Use ISNULL to overcome it.

Example:

SELECT (ISNULL(field1, '') + '' + ISNULL(field2, '')+ '' + ISNULL(field3, '')) FROM table1

This will then replace your NULL content with an empty string which will preserve the concatentation operation from evaluating as an overall NULL result.

Get IPv4 addresses from Dns.GetHostEntry()

To find all valid address list this is the code I have used

public static IEnumerable<string> GetAddresses()
{
      var host = Dns.GetHostEntry(Dns.GetHostName());
      return (from ip in host.AddressList where ip.AddressFamily == AddressFamily.lo select ip.ToString()).ToList();
}

MongoDB or CouchDB - fit for production?

I'm the CTO of 10gen (developers of MongoDB) so I'm a bit biased, but I also manage a few sites that are using MongoDB in production.

businessinsider has been using mongo in production for over a year now. They are using it for everything from users and blog posts, to every image on the site.

shopwiki is using it for a few things including real time analytics and a caching layer. They are doing over 1000 writes per second to a fairly large database.

If you go to the mongodb Production Deployments page you'll see some people who are using mongo in production.

If you have any questions about the scale or scope of production deployments, post on our user list and we'll be more than happy to help.

sklearn plot confusion matrix with labels

UPDATE:

In scikit-learn 0.22, there's a new feature to plot the confusion matrix directly.

See the documentation: sklearn.metrics.plot_confusion_matrix


OLD ANSWER:

I think it's worth mentioning the use of seaborn.heatmap here.

import seaborn as sns
import matplotlib.pyplot as plt     

ax= plt.subplot()
sns.heatmap(cm, annot=True, ax = ax); #annot=True to annotate cells

# labels, title and ticks
ax.set_xlabel('Predicted labels');ax.set_ylabel('True labels'); 
ax.set_title('Confusion Matrix'); 
ax.xaxis.set_ticklabels(['business', 'health']); ax.yaxis.set_ticklabels(['health', 'business']);

enter image description here

Importing data from a JSON file into R

An alternative package is RJSONIO. To convert a nested list, lapply can help:

l <- fromJSON('[{"winner":"68694999",  "votes":[ 
   {"ts":"Thu Mar 25 03:13:01 UTC 2010", "user":{"name":"Lamur","user_id":"68694999"}},   
   {"ts":"Thu Mar 25 03:13:08 UTC 2010", "user":{"name":"Lamur","user_id":"68694999"}}],   
  "lastVote":{"timestamp":1269486788526,"user":
   {"name":"Lamur","user_id":"68694999"}},"startPrice":0}]'
)
m <- lapply(
    l[[1]]$votes, 
    function(x) c(x$user['name'], x$user['user_id'], x['ts'])
)
m <- do.call(rbind, m)

gives information on the votes in your example.

Initializing select with AngularJS and ng-repeat

The fact that angular is injecting an empty option element to the select is that the model object binded to it by default comes with an empty value in when initialized.

If you want to select a default option then you can probably can set it on the scope in the controller

$scope.filterCondition.operator = "your value here";

If you want to an empty option placeholder, this works for me

<select ng-model="filterCondition.operator" ng-options="operator.id as operator.name for operator in operators">
  <option value="">Choose Operator</option>
</select>

Apache: "AuthType not set!" 500 Error

You can try sudo a2enmod rewrite if you use it in your config.

Getting the difference between two sets

Try this

test2.removeAll(test1);

Set#removeAll

Removes from this set all of its elements that are contained in the specified collection (optional operation). If the specified collection is also a set, this operation effectively modifies this set so that its value is the asymmetric set difference of the two sets.

How to import a CSS file in a React Component

In cases where you just want to inject some styles from a stylesheet into a component without bundling in the whole stylesheet I recommend https://github.com/glortho/styled-import. For example:

const btnStyle = styledImport.react('../App.css', '.button')

// btnStyle is now { color: 'blue' } or whatever other rules you have in `.button`.

NOTE: I am the author of this lib, and I built it for cases where mass imports of styles and CSS modules are not the best or most viable solution.

How to call a JavaScript function from PHP?

You may not be able to directly do this, but the Xajax library is pretty close to what you want. I will demonstrate with an example. Here's a button on a webpage:

<button onclick="xajax_addCity();">Add New City</button> 

Our intuitive guess would be that xajax_addCity() is a Javascript function, right? Well, right and wrong. The cool thing Xajax allows is that we don't have any JS function called xajax_addCity(), but what we do have is a PHP function called addCity() that can do whatever PHP does!

<?php function addCity() { echo "Wow!"; } ?>

Think about it for a minute. We are virtually invoking a PHP function from Javascript code! That over-simplified example was just to whet the appetite, a better explanation is on the Xajax site, have fun!

Get the selected option id with jQuery

Th easiest way to this is var id = $(this).val(); from inside an event like on change.

Why is a primary-foreign key relation required when we can join without it?

A primary key is not required. A foreign key is not required either. You can construct a query joining two tables on any column you wish as long as the datatypes either match or are converted to match. No relationship needs to explicitly exist.

To do this you use an outer join:

select tablea.code, tablea.name, tableb.location from tablea left outer join 
tableb on tablea.code = tableb.code

join with out relation

SQL join

Python syntax for "if a or b or c but not all of them"

I'd go for:

conds = iter([a, b, c])
if any(conds) and not any(conds):
    # okay...

I think this should short-circuit fairly efficiently

Explanation

By making conds an iterator, the first use of any will short circuit and leave the iterator pointing to the next element if any item is true; otherwise, it will consume the entire list and be False. The next any takes the remaining items in the iterable, and makes sure than there aren't any other true values... If there are, the whole statement can't be true, thus there isn't one unique element (so short circuits again). The last any will either return False or will exhaust the iterable and be True.

note: the above checks if only a single condition is set


If you want to check if one or more items, but not every item is set, then you can use:

not all(conds) and any(conds)

Stacked Bar Plot in R

The dataset:

dat <- read.table(text = "A   B   C   D   E   F    G
1 480 780 431 295 670 360  190
2 720 350 377 255 340 615  345
3 460 480 179 560  60 735 1260
4 220 240 876 789 820 100   75", header = TRUE)

Now you can convert the data frame into a matrix and use the barplot function.

barplot(as.matrix(dat))

enter image description here

Align <div> elements side by side

keep it simple

<div align="center">
<div style="display: inline-block"> <img src="img1.png"> </div>
<div style="display: inline-block"> <img src="img2.png"> </div>
</div>

Convert to/from DateTime and Time in Ruby

You can use to_date, e.g.

> Event.last.starts_at
=> Wed, 13 Jan 2021 16:49:36.292979000 CET +01:00
> Event.last.starts_at.to_date
=> Wed, 13 Jan 2021

How do you add swap to an EC2 instance?

After applying the steps mentioned by ajtrichards you can check if your amazon free tier instance is using swap using this command

cat /proc/meminfo

result:

ubuntu@ip-172-31-24-245:/$ cat /proc/meminfo
MemTotal:         604340 kB
MemFree:            8524 kB
Buffers:            3380 kB
Cached:           398316 kB
SwapCached:            0 kB
Active:           165476 kB
Inactive:         384556 kB
Active(anon):     141344 kB
Inactive(anon):     7248 kB
Active(file):      24132 kB
Inactive(file):   377308 kB
Unevictable:           0 kB
Mlocked:               0 kB

SwapTotal: 1048572 kB

SwapFree: 1048572 kB

Dirty:                 0 kB
Writeback:             0 kB
AnonPages:        148368 kB
Mapped:            14304 kB
Shmem:               256 kB
Slab:              26392 kB
SReclaimable:      18648 kB
SUnreclaim:         7744 kB
KernelStack:         736 kB
PageTables:         5060 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     1350740 kB
Committed_AS:     623908 kB
VmallocTotal:   34359738367 kB
VmallocUsed:        7420 kB
VmallocChunk:   34359728748 kB
HardwareCorrupted:     0 kB
AnonHugePages:         0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:      637952 kB
DirectMap2M:           0 kB

Pandas Replace NaN with blank/empty string

If you are converting DataFrame to JSON, NaN will give error so best solution is in this use case is to replace NaN with None.
Here is how:

df1 = df.where((pd.notnull(df)), None)

How are ssl certificates verified?

The client has a pre-seeded store of SSL certificate authorities' public keys. There must be a chain of trust from the certificate for the server up through intermediate authorities up to one of the so-called "root" certificates in order for the server to be trusted.

You can examine and/or alter the list of trusted authorities. Often you do this to add a certificate for a local authority that you know you trust - like the company you work for or the school you attend or what not.

The pre-seeded list can vary depending on which client you use. The big SSL certificate vendors insure that their root certs are in all the major browsers ($$$).

Monkey-in-the-middle attacks are "impossible" unless the attacker has the private key of a trusted root certificate. Since the corresponding certificates are widely deployed, the exposure of such a private key would have serious implications for the security of eCommerce generally. Because of that, those private keys are very, very closely guarded.

Bootstrap: How to center align content inside column?

Want to center an image? Very easy, Bootstrap comes with two classes, .center-block and text-center.

Use the former in the case of your image being a BLOCK element, for example, adding img-responsive class to your img makes the img a block element. You should know this if you know how to navigate in the web console and see applied styles to an element.

Don't want to use a class? No problem, here is the CSS bootstrap uses. You can make a custom class or write a CSS rule for the element to match the Bootstrap class.

 // In case you're dealing with a block element apply this to the element itself 
.center-block {
   margin-left:auto;
   margin-right:auto;
   display:block;
}

// In case you're dealing with a inline element apply this to the parent 
.text-center {
   text-align:center
}

Adding a guideline to the editor in Visual Studio

This is originally from Sara's blog.

It also works with almost any version of Visual Studio, you just need to change the "8.0" in the registry key to the appropriate version number for your version of Visual Studio.

The guide line shows up in the Output window too. (Visual Studio 2010 corrects this, and the line only shows up in the code editor window.)

You can also have the guide in multiple columns by listing more than one number after the color specifier:

RGB(230,230,230), 4, 80

Puts a white line at column 4 and column 80. This should be the value of a string value Guides in "Text Editor" key (see bellow).

Be sure to pick a line color that will be visisble on your background. This color won't show up on the default background color in VS. This is the value for a light grey: RGB(221, 221, 221).

Here are the registry keys that I know of:

Visual Studio 2010: HKCU\Software\Microsoft\VisualStudio\10.0\Text Editor

Visual Studio 2008: HKCU\Software\Microsoft\VisualStudio\9.0\Text Editor

Visual Studio 2005: HKCU\Software\Microsoft\VisualStudio\8.0\Text Editor

Visual Studio 2003: HKCU\Software\Microsoft\VisualStudio\7.1\Text Editor

For those running Visual Studio 2010, you may want to install the following extensions rather than changing the registry yourself:

These are also part of the Productivity Power Tools, which includes many other very useful extensions.

function declaration isn't a prototype

Try:

extern int testlib(void);

jQuery: If this HREF contains

You could just outright select the elements of interest.

$('a[href*="?"]').each(function() {
    alert('Contains question mark');
});

http://jsfiddle.net/mattball/TzUN3/

Note that you were using the attribute-ends-with selector, the above code uses the attribute-contains selector, which is what it sounds like you're actually aiming for.

A more useful statusline in vim?

set statusline=%<%f%m\ \[%{&ff}:%{&fenc}:%Y]\ %{getcwd()}\ \ \[%{strftime('%Y/%b/%d\ %a\ %I:%M\ %p')}\]\ %=\ Line:%l\/%L\ Column:%c%V\ %P

This is mine, give as a suggestion

Simple regular expression for a decimal with a precision of 2

 function DecimalNumberValidation() {
        var amounttext = ;
            if (!(/^[-+]?\d*\.?\d*$/.test(document.getElementById('txtRemittanceNumber').value))){
            alert('Please enter only numbers into amount textbox.')
            }
            else
            {
            alert('Right Number');
            }
    }

function will validate any decimal number weather number has decimal places or not, it will say "Right Number" other wise "Please enter only numbers into amount textbox." alert message will come up.

Thanks... :)

Where does forever store console.log output?

It is a old question but i ran across the same issues. If you wanna see live output you can run

forever logs

This would show the path of the logs file as well as the number of the script. You can then use

forever logs 0 -f

0 should be replaced by the number of the script you wanna see the output for.

What is the difference between cssSelector & Xpath and which is better with respect to performance for cross browser testing?

I’m going to hold the unpopular on SO selenium tag opinion that XPath is preferable to CSS in the longer run.

This long post has two sections - first I'll put a back-of-the-napkin proof the performance difference between the two is 0.1-0.3 milliseconds (yes; that's 100 microseconds), and then I'll share my opinion why XPath is more powerful.


Performance difference

Let's first tackle "the elephant in the room" – that xpath is slower than css.

With the current cpu power (read: anything x86 produced since 2013), even on browserstack/saucelabs/aws VMs, and the development of the browsers (read: all the popular ones in the last 5 years) that is hardly the case. The browser's engines have developed, the support of xpath is uniform, IE is out of the picture (hopefully for most of us). This comparison in the other answer is being cited all over the place, but it is very contextual – how many are running – or care about – automation against IE8?

If there is a difference, it is in a fraction of a millisecond.

Yet, most higher-level frameworks add at least 1ms of overhead over the raw selenium call anyways (wrappers, handlers, state storing etc); my personal weapon of choice – RobotFramework – adds at least 2ms, which I am more than happy to sacrifice for what it provides. A network roundtrip from an AWS us-east-1 to BrowserStack's hub is usually 11 milliseconds.

So with remote browsers if there is a difference between xpath and css, it is overshadowed by everything else, in orders of magnitude.


The measurements

There are not that many public comparisons (I've really seen only the cited one), so – here's a rough single-case, dummy and simple one.
It will locate an element by the two strategies X times, and compare the average time for that.

The target – BrowserStack's landing page, and its "Sign Up" button; a screenshot of the html as writing this post:

enter image description here

Here's the test code (python):

from selenium import webdriver
import timeit


if __name__ == '__main__':

    xpath_locator = '//div[@class="button-section col-xs-12 row"]'
    css_locator = 'div.button-section.col-xs-12.row'

    repetitions = 1000

    driver = webdriver.Chrome()
    driver.get('https://www.browserstack.com/')

    css_time = timeit.timeit("driver.find_element_by_css_selector(css_locator)", 
                             number=repetitions, globals=globals())
    xpath_time = timeit.timeit('driver.find_element_by_xpath(xpath_locator)', 
                             number=repetitions, globals=globals())

    driver.quit()

    print("css total time {} repeats: {:.2f}s, per find: {:.2f}ms".
          format(repetitions, css_time, (css_time/repetitions)*1000))
    print("xpath total time for {} repeats: {:.2f}s, per find: {:.2f}ms".
          format(repetitions, xpath_time, (xpath_time/repetitions)*1000))

For those not familiar with Python – it opens the page, and finds the element – first with the css locator, then with the xpath; the find operation is repeated 1,000 times. The output is the total time in seconds for the 1,000 repetitions, and average time for one find in milliseconds.

The locators are:

  • for xpath – "a div element having this exact class value, somewhere in the DOM";
  • the css is similar – "a div element with this class, somewhere in the DOM".

Deliberately chosen not to be over-tuned; also, the class selector is cited for the css as "the second fastest after an id".

The environment – Chrome v66.0.3359.139, chromedriver v2.38, cpu: ULV Core M-5Y10 usually running at 1.5GHz (yes, a "word-processing" one, not even a regular i7 beast).

Here's the output:

css total time 1000 repeats: 8.84s, per find: 8.84ms

xpath total time for 1000 repeats: 8.52s, per find: 8.52ms

Obviously the per find timings are pretty close; the difference is 0.32 milliseconds. Don't jump "the xpath is faster" – sometimes it is, sometimes it's css.


Let's try with another set of locators, a tiny-bit more complicated – an attribute having a substring (common approach at least for me, going after an element's class when a part of it bears functional meaning):

xpath_locator = '//div[contains(@class, "button-section")]'
css_locator = 'div[class~=button-section]'

The two locators are again semantically the same – "find a div element having in its class attribute this substring".
Here are the results:

css total time 1000 repeats: 8.60s, per find: 8.60ms

xpath total time for 1000 repeats: 8.75s, per find: 8.75ms

Diff of 0.15ms.


As an exercise - the same test as done in the linked blog in the comments/other answer - the test page is public, and so is the testing code.

They are doing a couple of things in the code - clicking on a column to sort by it, then getting the values, and checking the UI sort is correct.
I'll cut it - just get the locators, after all - this is the root test, right?

The same code as above, with these changes in:

  • The url is now http://the-internet.herokuapp.com/tables; there are 2 tests.

  • The locators for the first one - "Finding Elements By ID and Class" - are:

css_locator = '#table2 tbody .dues'
xpath_locator = "//table[@id='table2']//tr/td[contains(@class,'dues')]"

And here is the outcome:

css total time 1000 repeats: 8.24s, per find: 8.24ms

xpath total time for 1000 repeats: 8.45s, per find: 8.45ms

Diff of 0.2 milliseconds.

The "Finding Elements By Traversing":

css_locator = '#table1 tbody tr td:nth-of-type(4)'
xpath_locator = "//table[@id='table1']//tr/td[4]"

The result:

css total time 1000 repeats: 9.29s, per find: 9.29ms

xpath total time for 1000 repeats: 8.79s, per find: 8.79ms

This time it is 0.5 ms (in reverse, xpath turned out "faster" here).

So 5 years later (better browsers engines) and focusing only on the locators performance (no actions like sorting in the UI, etc), the same testbed - there is practically no difference between CSS and XPath.


So, out of xpath and css, which of the two to choose for performance? The answer is simple – choose locating by id.

Long story short, if the id of an element is unique (as it's supposed to be according to the specs), its value plays an important role in the browser's internal representation of the DOM, and thus is usually the fastest.

Yet, unique and constant (e.g. not auto-generated) ids are not always available, which brings us to "why XPath if there's CSS?"


The XPath advantage

With the performance out of the picture, why do I think xpath is better? Simple – versatility, and power.

Xpath is a language developed for working with XML documents; as such, it allows for much more powerful constructs than css.
For example, navigation in every direction in the tree – find an element, then go to its grandparent and search for a child of it having certain properties.
It allows embedded boolean conditions – cond1 and not(cond2 or not(cond3 and cond4)); embedded selectors – "find a div having these children with these attributes, and then navigate according to it".
XPath allows searching based on a node's value (its text) – however frowned upon this practice is, it does come in handy especially in badly structured documents (no definite attributes to step on, like dynamic ids and classes - locate the element by its text content).

The stepping in css is definitely easier – one can start writing selectors in a matter of minutes; but after a couple of days of usage, the power and possibilities xpath has quickly overcomes css.
And purely subjective – a complex css is much harder to read than a complex xpath expression.

Outro ;)

Finally, again very subjective - which one to chose?

IMO, there is no right or wrong choice - they are different solutions to the same problem, and whatever is more suitable for the job should be picked.

Being "a fan" of XPath I'm not shy to use in my projects a mix of both - heck, sometimes it is much faster to just throw a CSS one, if I know it will do the work just fine.

Should we pass a shared_ptr by reference or by value?

Since C++11 you should take it by value over const& more often than you might think.

If you are taking the std::shared_ptr (rather than the underlying type T), then you are doing so because you want to do something with it.

If you would like to copy it somewhere, it makes more sense to take it by copy, and std::move it internally, rather than taking it by const& and then later copying it. This is because you allow the caller the option to in turn std::move the shared_ptr when calling your function, thus saving yourself a set of increment and decrement operations. Or not. That is, the caller of the function can decide whether or not he needs the std::shared_ptr around after calling the function, and depending on whether or not move or not. This is not achievable if you pass by const&, and thus it is then preferably to take it by value.

Of course, if the caller both needs his shared_ptr around for longer (thus can not std::move it) and you don't want to create a plain copy in the function (say you want a weak pointer, or you only sometimes want to copy it, depending on some condition), then a const& might still be preferable.

For example, you should do

void enqueue(std::shared<T> t) m_internal_queue.enqueue(std::move(t));

over

void enqueue(std::shared<T> const& t) m_internal_queue.enqueue(t);

Because in this case you always create a copy internally

OpenCV with Network Cameras

I just do it like this:

CvCapture *capture = cvCreateFileCapture("rtsp://camera-address");

Also make sure this dll is available at runtime else cvCreateFileCapture will return NULL

opencv_ffmpeg200d.dll

The camera needs to allow unauthenticated access too, usually set via its web interface. MJPEG format worked via rtsp but MPEG4 didn't.

hth

Si

iPhone UIView Animation Best Practice

let's do try and checkout For Swift 3...

UIView.transition(with: mysuperview, duration: 0.75, options:UIViewAnimationOptions.transitionFlipFromRight , animations: {
    myview.removeFromSuperview()
}, completion: nil)

regex match any single character (one character only)

Simple answer

If you want to match single character, put it inside those brackets [ ]

Examples

  • match + ...... [+] or +
  • match a ...... a
  • match & ...... &

...and so on. You can check your regular expresion online on this site: https://regex101.com/

(updated based on comment)

Does Python have an argc argument?

dir(sys) says no. len(sys.argv) works, but in Python it is better to ask for forgiveness than permission, so

#!/usr/bin/python
import sys
try:
    in_file = open(sys.argv[1], "r")
except:
    sys.exit("ERROR. Can't read supplied filename.")
text = in_file.read()
print(text)
in_file.close()

works fine and is shorter.

If you're going to exit anyway, this would be better:

#!/usr/bin/python
import sys
text = open(sys.argv[1], "r").read()
print(text)

I'm using print() so it works in 2.7 as well as Python 3.

How to delete a character from a string using Python

def kill_char(string, n): # n = position of which character you want to remove
    begin = string[:n]    # from beginning to n (n not included)
    end = string[n+1:]    # n+1 through end of string
    return begin + end
print kill_char("EXAMPLE", 3)  # "M" removed

I have seen this somewhere here.

What is Cache-Control: private?

The Expires entity-header field gives the date/time after which the response is considered stale.The Cache-control:maxage field gives the age value (in seconds) bigger than which response is consider stale.

Althought above header field give a mechanism to client to decide whether to send request to the server. In some condition, the client send a request to sever and the age value of response is bigger then the maxage value ,dose it means server needs to send the resource to client? Maybe the resource never changed.

In order to resolve this problem, HTTP1.1 gives last-modifided head. The server gives the last modified date of the response to client. When the client need this resource, it will send If-Modified-Since head field to server. If this date is before the modified date of the resouce, the server will sends the resource to client and gives 200 code.Otherwise,it will returns 304 code to client and this means client can use the resource it cached.

Android: show soft keyboard automatically when focus is on an EditText

I found this example http://android-codes-examples.blogspot.com/2011/11/show-or-hide-soft-keyboard-on-opening.html. Add the following code just before alert.show().

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED,0);

Why Java Calendar set(int year, int month, int date) not returning correct date?

1 for month is February. The 30th of February is changed to 1st of March. You should set 0 for month. The best is to use the constant defined in Calendar:

c1.set(2000, Calendar.JANUARY, 30);

How do I properly 'printf' an integer and a string in C?

scanf("%s",str) scans only until it finds a whitespace character. With the input "A 1", it will scan only the first character, hence s2 points at the garbage that happened to be in str, since that array wasn't initialised.

JavaScript math, round to two decimal places

A small variation on the accepted answer. toFixed(2) returns a string, and you will always get two decimal places. These might be zeros. If you would like to suppress final zero(s), simply do this:

var discount = + ((price / listprice).toFixed(2));

Edited: I've just discovered what seems to be a bug in Firefox 35.0.1, which means that the above may give NaN with some values.
I've changed my code to

var discount = Math.round(price / listprice * 100) / 100;

This gives a number with up to two decimal places. If you wanted three, you would multiply and divide by 1000, and so on.
The OP wants two decimal places always, but if toFixed() is broken in Firefox it needs fixing first.
See https://bugzilla.mozilla.org/show_bug.cgi?id=1134388

HTML5 Canvas Resize (Downscale) Image High Quality?

Since your problem is to downscale your image, there is no point in talking about interpolation -which is about creating pixel-. The issue here is downsampling.

To downsample an image, we need to turn each square of p * p pixels in the original image into a single pixel in the destination image.

For performances reasons Browsers do a very simple downsampling : to build the smaller image, they will just pick ONE pixel in the source and use its value for the destination. which 'forgets' some details and adds noise.

Yet there's an exception to that : since the 2X image downsampling is very simple to compute (average 4 pixels to make one) and is used for retina/HiDPI pixels, this case is handled properly -the Browser does make use of 4 pixels to make one-.

BUT... if you use several time a 2X downsampling, you'll face the issue that the successive rounding errors will add too much noise.
What's worse, you won't always resize by a power of two, and resizing to the nearest power + a last resizing is very noisy.

What you seek is a pixel-perfect downsampling, that is : a re-sampling of the image that will take all input pixels into account -whatever the scale-.
To do that we must compute, for each input pixel, its contribution to one, two, or four destination pixels depending wether the scaled projection of the input pixels is right inside a destination pixels, overlaps an X border, an Y border, or both.
( A scheme would be nice here, but i don't have one. )

Here's an example of canvas scale vs my pixel perfect scale on a 1/3 scale of a zombat.

Notice that the picture might get scaled in your Browser, and is .jpegized by S.O..
Yet we see that there's much less noise especially in the grass behind the wombat, and the branches on its right. The noise in the fur makes it more contrasted, but it looks like he's got white hairs -unlike source picture-.
Right image is less catchy but definitively nicer.

enter image description here

Here's the code to do the pixel perfect downscaling :

fiddle result : http://jsfiddle.net/gamealchemist/r6aVp/embedded/result/
fiddle itself : http://jsfiddle.net/gamealchemist/r6aVp/

// scales the image by (float) scale < 1
// returns a canvas containing the scaled image.
function downScaleImage(img, scale) {
    var imgCV = document.createElement('canvas');
    imgCV.width = img.width;
    imgCV.height = img.height;
    var imgCtx = imgCV.getContext('2d');
    imgCtx.drawImage(img, 0, 0);
    return downScaleCanvas(imgCV, scale);
}

// scales the canvas by (float) scale < 1
// returns a new canvas containing the scaled image.
function downScaleCanvas(cv, scale) {
    if (!(scale < 1) || !(scale > 0)) throw ('scale must be a positive number <1 ');
    var sqScale = scale * scale; // square scale = area of source pixel within target
    var sw = cv.width; // source image width
    var sh = cv.height; // source image height
    var tw = Math.floor(sw * scale); // target image width
    var th = Math.floor(sh * scale); // target image height
    var sx = 0, sy = 0, sIndex = 0; // source x,y, index within source array
    var tx = 0, ty = 0, yIndex = 0, tIndex = 0; // target x,y, x,y index within target array
    var tX = 0, tY = 0; // rounded tx, ty
    var w = 0, nw = 0, wx = 0, nwx = 0, wy = 0, nwy = 0; // weight / next weight x / y
    // weight is weight of current source point within target.
    // next weight is weight of current source point within next target's point.
    var crossX = false; // does scaled px cross its current px right border ?
    var crossY = false; // does scaled px cross its current px bottom border ?
    var sBuffer = cv.getContext('2d').
    getImageData(0, 0, sw, sh).data; // source buffer 8 bit rgba
    var tBuffer = new Float32Array(3 * tw * th); // target buffer Float32 rgb
    var sR = 0, sG = 0,  sB = 0; // source's current point r,g,b
    /* untested !
    var sA = 0;  //source alpha  */    

    for (sy = 0; sy < sh; sy++) {
        ty = sy * scale; // y src position within target
        tY = 0 | ty;     // rounded : target pixel's y
        yIndex = 3 * tY * tw;  // line index within target array
        crossY = (tY != (0 | ty + scale)); 
        if (crossY) { // if pixel is crossing botton target pixel
            wy = (tY + 1 - ty); // weight of point within target pixel
            nwy = (ty + scale - tY - 1); // ... within y+1 target pixel
        }
        for (sx = 0; sx < sw; sx++, sIndex += 4) {
            tx = sx * scale; // x src position within target
            tX = 0 |  tx;    // rounded : target pixel's x
            tIndex = yIndex + tX * 3; // target pixel index within target array
            crossX = (tX != (0 | tx + scale));
            if (crossX) { // if pixel is crossing target pixel's right
                wx = (tX + 1 - tx); // weight of point within target pixel
                nwx = (tx + scale - tX - 1); // ... within x+1 target pixel
            }
            sR = sBuffer[sIndex    ];   // retrieving r,g,b for curr src px.
            sG = sBuffer[sIndex + 1];
            sB = sBuffer[sIndex + 2];

            /* !! untested : handling alpha !!
               sA = sBuffer[sIndex + 3];
               if (!sA) continue;
               if (sA != 0xFF) {
                   sR = (sR * sA) >> 8;  // or use /256 instead ??
                   sG = (sG * sA) >> 8;
                   sB = (sB * sA) >> 8;
               }
            */
            if (!crossX && !crossY) { // pixel does not cross
                // just add components weighted by squared scale.
                tBuffer[tIndex    ] += sR * sqScale;
                tBuffer[tIndex + 1] += sG * sqScale;
                tBuffer[tIndex + 2] += sB * sqScale;
            } else if (crossX && !crossY) { // cross on X only
                w = wx * scale;
                // add weighted component for current px
                tBuffer[tIndex    ] += sR * w;
                tBuffer[tIndex + 1] += sG * w;
                tBuffer[tIndex + 2] += sB * w;
                // add weighted component for next (tX+1) px                
                nw = nwx * scale
                tBuffer[tIndex + 3] += sR * nw;
                tBuffer[tIndex + 4] += sG * nw;
                tBuffer[tIndex + 5] += sB * nw;
            } else if (crossY && !crossX) { // cross on Y only
                w = wy * scale;
                // add weighted component for current px
                tBuffer[tIndex    ] += sR * w;
                tBuffer[tIndex + 1] += sG * w;
                tBuffer[tIndex + 2] += sB * w;
                // add weighted component for next (tY+1) px                
                nw = nwy * scale
                tBuffer[tIndex + 3 * tw    ] += sR * nw;
                tBuffer[tIndex + 3 * tw + 1] += sG * nw;
                tBuffer[tIndex + 3 * tw + 2] += sB * nw;
            } else { // crosses both x and y : four target points involved
                // add weighted component for current px
                w = wx * wy;
                tBuffer[tIndex    ] += sR * w;
                tBuffer[tIndex + 1] += sG * w;
                tBuffer[tIndex + 2] += sB * w;
                // for tX + 1; tY px
                nw = nwx * wy;
                tBuffer[tIndex + 3] += sR * nw;
                tBuffer[tIndex + 4] += sG * nw;
                tBuffer[tIndex + 5] += sB * nw;
                // for tX ; tY + 1 px
                nw = wx * nwy;
                tBuffer[tIndex + 3 * tw    ] += sR * nw;
                tBuffer[tIndex + 3 * tw + 1] += sG * nw;
                tBuffer[tIndex + 3 * tw + 2] += sB * nw;
                // for tX + 1 ; tY +1 px
                nw = nwx * nwy;
                tBuffer[tIndex + 3 * tw + 3] += sR * nw;
                tBuffer[tIndex + 3 * tw + 4] += sG * nw;
                tBuffer[tIndex + 3 * tw + 5] += sB * nw;
            }
        } // end for sx 
    } // end for sy

    // create result canvas
    var resCV = document.createElement('canvas');
    resCV.width = tw;
    resCV.height = th;
    var resCtx = resCV.getContext('2d');
    var imgRes = resCtx.getImageData(0, 0, tw, th);
    var tByteBuffer = imgRes.data;
    // convert float32 array into a UInt8Clamped Array
    var pxIndex = 0; //  
    for (sIndex = 0, tIndex = 0; pxIndex < tw * th; sIndex += 3, tIndex += 4, pxIndex++) {
        tByteBuffer[tIndex] = Math.ceil(tBuffer[sIndex]);
        tByteBuffer[tIndex + 1] = Math.ceil(tBuffer[sIndex + 1]);
        tByteBuffer[tIndex + 2] = Math.ceil(tBuffer[sIndex + 2]);
        tByteBuffer[tIndex + 3] = 255;
    }
    // writing result to canvas.
    resCtx.putImageData(imgRes, 0, 0);
    return resCV;
}

It is quite memory greedy, since a float buffer is required to store the intermediate values of the destination image (-> if we count the result canvas, we use 6 times the source image's memory in this algorithm).
It is also quite expensive, since each source pixel is used whatever the destination size, and we have to pay for the getImageData / putImageDate, quite slow also.
But there's no way to be faster than process each source value in this case, and situation is not that bad : For my 740 * 556 image of a wombat, processing takes between 30 and 40 ms.

Redirect from asp.net web api post action

You can check this

[Route("Report/MyReport")]
public IHttpActionResult GetReport()
{

   string url = "https://localhost:44305/Templates/ReportPage.html";

   System.Uri uri = new System.Uri(url);

   return Redirect(uri);
}

Using JQuery hover with HTML image map

I found this wonderful mapping script (mapper.js) that I have used in the past. What's different about it is you can hover over the map or a link on your page to make the map area highlight. Sadly it's written in javascript and requires a lot of in-line coding in the HTML - I would love to see this script ported over to jQuery :P

Also, check out all the demos! I think this example could almost be made into a simple online game (without using flash) - make sure you click on the different camera angles.

Maven 3 warnings about build.plugins.plugin.version

Run like:

  $ mvn help:describe -DartifactId=maven-war-plugin -DgroupId=org.apache.maven.plugins

for plug-in that have no version. You get output:

Name: Maven WAR Plugin
Description: Builds a Web Application Archive (WAR) file from the project
  output and its dependencies.
Group Id: org.apache.maven.plugins
Artifact Id: maven-war-plugin
Version: 2.2
Goal Prefix: war

Use version that shown in output.

UPDATE If you want to select among list of versions, use http://search.maven.org/ or http://mvnrepository.com/ Note that your favorite Java IDE must have Maven package search dialog. Just check docs.

SUPER UPDATE I also use:

$ mvn dependency:tree
$ mvn dependency:list
$ mvn dependency:resolve
$ mvn dependency:resolve-plugins  # <-- THIS

Recently I discover how to get latest version for plug-in (or library) so no longer needs for googling or visiting Maven Central:

$ mvn versions:display-dependency-updates
$ mvn versions:display-plugin-updates     # <-- THIS

ng-if check if array is empty

To overcome the null / undefined issue, try using the ? operator to check existence:

<p ng-if="post?.capabilities?.items?.length > 0">
  • Sidenote, if anyone got to this page looking for an Ionic Framework answer, ensure you use *ngIf:

    <p *ngIf="post?.capabilities?.items?.length > 0">
    

C# Help reading foreign characters using StreamReader

File.OpenText() always uses an UTF-8 StreamReader implicitly. Create your own StreamReader instance instead and specify the desired encoding. like

using (StreamReader reader =  new StreamReader(@"C:\test.txt", Encoding.Default)
 {
 // ...
 }

Set Jackson Timezone for Date deserialization

I had same problem with Calendar deserialization, solved extending CalendarDeserializer.
It forces UTC Timezone
I paste the code if someone need it:

@JacksonStdImpl
public class UtcCalendarDeserializer extends CalendarDeserializer {

    TimeZone TZ_UTC = TimeZone.getTimeZone("UTC");

    @Override
    public Calendar deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
        JsonToken t = jp.getCurrentToken();
        if (t == JsonToken.VALUE_NUMBER_INT) {
            Calendar cal = Calendar.getInstance(TZ_UTC);
            cal.clear();
            cal.setTimeInMillis(jp.getLongValue());

            return cal;
        }

        return super.deserialize(jp, ctxt);
    }
}

in JSON model class just annotate the field with:

@JsonDeserialize(using = UtcCalendarDeserializer.class)
private Calendar myCalendar;

Git Extensions: Win32 error 487: Couldn't reserve space for cygwin's heap, Win32 error 0

I have encountered this issue witht he LPCEXpresso building.if you have the C:\MinGW\bin in the PATH. somehow I had to remove it to get rid of this issue since some other MinGW like based too

Using a string variable as a variable name

You can use setattr

name  = 'varname'
value = 'something'

setattr(self, name, value) #equivalent to: self.varname= 'something'

print (self.varname)
#will print 'something'

But, since you should inform an object to receive the new variable, this only works inside classes or modules.

Table row and column number in jQuery

$('td').click(function() {
    var myCol = $(this).index();
    var $tr = $(this).closest('tr');
    var myRow = $tr.index();
});

Differences between key, superkey, minimal superkey, candidate key and primary key

Superkey

A superkey is a combination of attributes that can be uniquely used to identify a 
database record. A table might have many superkeys.Candidate keys are a special subset
of superkeys that do not have any extraneous information in them.

Examples: Imagine a table with the fields <Name>, <Age>, <SSN> and <Phone Extension>.
This table has many possible superkeys. Three of these are <SSN>, <Phone Extension, Name>
and <SSN, Name>.Of those listed, only <SSN> is a **candidate key**, as the others
contain information not necessary to uniquely identify records.

An implementation of the fast Fourier transform (FFT) in C#

AForge.net is a free (open-source) library with Fast Fourier Transform support. (See Sources/Imaging/ComplexImage.cs for usage, Sources/Math/FourierTransform.cs for implemenation)

Using union and order by clause in mysql

Just use order by column number (don't use column name). Every query returns some columns, so you can order by any desired column using it's number.

validate a dropdownlist in asp.net mvc

I just can't believe that there are people still using ViewData/ViewBag in ASP.NET MVC 3 instead of having strongly typed views and view models:

public class MyViewModel
{
    [Required]
    public string CategoryId { get; set; }

    public IEnumerable<Category> Categories { get; set; }
}

and in your controller:

public class HomeController: Controller
{
    public ActionResult Index()
    {
        var model = new MyViewModel
        {
            Categories = Repository.GetCategories()
        }
        return View(model);
    }

    [HttpPost]
    public ActionResult Index(MyViewModel model)
    {
        if (!ModelState.IsValid)
        {
            // there was a validation error =>
            // rebind categories and redisplay view
            model.Categories = Repository.GetCategories();
            return View(model);
        }
        // At this stage the model is OK => do something with the selected category
        return RedirectToAction("Success");
    }
}

and then in your strongly typed view:

@Html.DropDownListFor(
    x => x.CategoryId, 
    new SelectList(Model.Categories, "ID", "CategoryName"), 
    "-- Please select a category --"
)
@Html.ValidationMessageFor(x => x.CategoryId)

Also if you want client side validation don't forget to reference the necessary scripts:

<script src="@Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script>

How do I get the current year using SQL on Oracle?

Yet another option would be:

SELECT * FROM mytable
 WHERE TRUNC(mydate, 'YEAR') = TRUNC(SYSDATE, 'YEAR');

Why am I getting "Cannot Connect to Server - A network-related or instance-specific error"?

I am solving that problem by opening Services then start running Sql Server (Sqlexpress) service.

service Image

Can't ignore UserInterfaceState.xcuserstate

In case the file keeps showing up even after doing everything mentioned here, make sure that this checkbox in Xcode settings is unchecked:

enter image description here

Most concise way to convert a Set<T> to a List<T>

Considering that we have Set<String> stringSet we can use following:

Plain Java

List<String> strList = new ArrayList<>(stringSet);

Guava

List<String> strList = Lists.newArrayList(stringSet);

Apache Commons

List<String> strList = new ArrayList<>();
CollectionUtils.addAll(strList, stringSet);

Java 10 (Unmodifiable List)

List<String> strList = List.copyOf(stringSet);
List<String> strList = stringSet.stream().collect(Collectors.toUnmodifiableList());

Java 8 (Modifiable Lists)

import static java.util.stream.Collectors.*;
List<String> stringList1 = stringSet.stream().collect(toList());

As per the doc for the method toList()

There are no guarantees on the type, mutability, serializability, or thread-safety of the List returned; if more control over the returned List is required, use toCollection(Supplier).

So if we need a specific implementation e.g. ArrayList we can get it this way:

List<String> stringList2 = stringSet.stream().
                              collect(toCollection(ArrayList::new));

Java 8 (Unmodifiable Lists)

We can make use of Collections::unmodifiableList method and wrap the list returned in previous examples. We can also write our own custom method as:

class ImmutableCollector {
    public static <T> Collector<T, List<T>, List<T>> toImmutableList(Supplier<List<T>> supplier) {
            return Collector.of( supplier, List::add, (left, right) -> {
                        left.addAll(right);
                        return left;
                    }, Collections::unmodifiableList);
        }
}

And then use it as:

List<String> stringList3 = stringSet.stream()
             .collect(ImmutableCollector.toImmutableList(ArrayList::new)); 

Another possibility is to make use of collectingAndThen method which allows some final transformation to be done before returning result:

    List<String> stringList4 = stringSet.stream().collect(collectingAndThen(
      toCollection(ArrayList::new),Collections::unmodifiableList));

One point to note is that the method Collections::unmodifiableList returns an unmodifiable view of the specified list, as per doc. An unmodifiable view collection is a collection that is unmodifiable and is also a view onto a backing collection. Note that changes to the backing collection might still be possible, and if they occur, they are visible through the unmodifiable view. But the collector method Collectors.unmodifiableList returns truly immutable list in Java 10.

Download the Android SDK components for offline install

I work behind a firewall on windows and I have the Same problem. But I managed to fix it:

  • Close all your internet applications (browsers, downloading tools etc...)
  • Start -> Execute -> type cmd then hit Enter (displays the command prompt)
  • Type netstat
  • In the results returned, find your Proxy address :

    TCP YOURMACHINENAME:PORT DISTANTMACHINE1:PORT
    TCP YOURMACHINENAME:PORT DISTANTMACHINE2:PORT
    TCP YOURMACHINENAME:PORT DISTANTMACHINE3:PORT
    
  • Your proxy address is one of the DISTANTMACHINEx

  • Your proxy port is the port following the ":"
  • Retype this proxy address and the proxy port in the "setting" page of android SDK manager
  • Tick "force https...http://"
  • Retry

How do I loop through or enumerate a JavaScript object?

Besause the asker's ['ultimate goal is to loop through some key value pairs'] and finally don't looking for a loop.

var p ={"p1":"value1","p2":"value2","p3":"value3"};
if('p1' in p){
  var val=p['p1'];
  ...
}

Error parsing yaml file: mapping values are not allowed here

Or, if spacing is not the problem, it might want the parent directory name rather than the file name.

Not $ dev_appserver helloapp.py
But $ dev_appserver hello/

For example:

Johns-Mac:hello john$ dev_appserver.py helloworld.py
Traceback (most recent call last):
  File "/usr/local/bin/dev_appserver.py", line 82, in <module>
    _run_file(__file__, globals())
...
  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/yaml_listener.py", line 212, in _GenerateEventParameters
    raise yaml_errors.EventListenerYAMLError(e)
google.appengine.api.yaml_errors.EventListenerYAMLError: mapping values are not allowed here
  in "helloworld.py", line 3, column 39

Versus

Johns-Mac:hello john$ cd ..
Johns-Mac:fbm john$ dev_appserver.py hello/
INFO     2014-09-15 11:44:27,828 api_server.py:171] Starting API server at: http://localhost:61049
INFO     2014-09-15 11:44:27,831 dispatcher.py:183] Starting module "default" running at: http://localhost:8080

String to object in JS

Since JSON.parse() method requires the Object keys to be enclosed within quotes for it to work correctly, we would first have to convert the string into a JSON formatted string before calling JSON.parse() method.

_x000D_
_x000D_
var obj = '{ firstName:"John", lastName:"Doe" }';_x000D_
_x000D_
var jsonStr = obj.replace(/(\w+:)|(\w+ :)/g, function(matchedStr) {_x000D_
  return '"' + matchedStr.substring(0, matchedStr.length - 1) + '":';_x000D_
});_x000D_
_x000D_
obj = JSON.parse(jsonStr); //converts to a regular object_x000D_
_x000D_
console.log(obj.firstName); // expected output: John_x000D_
console.log(obj.lastName); // expected output: Doe
_x000D_
_x000D_
_x000D_

This would work even if the string has a complex object (like the following) and it would still convert correctly. Just make sure that the string itself is enclosed within single quotes.

_x000D_
_x000D_
var strObj = '{ name:"John Doe", age:33, favorites:{ sports:["hoops", "baseball"], movies:["star wars", "taxi driver"]  }}';_x000D_
_x000D_
var jsonStr = strObj.replace(/(\w+:)|(\w+ :)/g, function(s) {_x000D_
  return '"' + s.substring(0, s.length-1) + '":';_x000D_
});_x000D_
_x000D_
var obj = JSON.parse(jsonStr);_x000D_
console.log(obj.favorites.movies[0]); // expected output: star wars
_x000D_
_x000D_
_x000D_

Is it correct to use alt tag for an anchor link?

For anchors, you should use title instead. alt is not valid atribute of a. See http://w3schools.com/tags/tag_a.asp

Connection timeout for SQL server

If you want to dynamically change it, I prefer using SqlConnectionStringBuilder .

It allows you to convert ConnectionString i.e. a string into class Object, All the connection string properties will become its Member.

In this case the real advantage would be that you don't have to worry about If the ConnectionTimeout string part is already exists in the connection string or not?

Also as it creates an Object and its always good to assign value in object rather than manipulating string.

Here is the code sample:

var sscsb = new SqlConnectionStringBuilder(_dbFactory.Database.ConnectionString);

sscsb.ConnectTimeout = 30;

var conn = new SqlConnection(sscsb.ConnectionString);

how to install gcc on windows 7 machine?

Following up on Mat's answer (use Cygwin), here are some detailed instructions for : installing gcc on Windows The packages you want are gcc, gdb and make. Cygwin installer lets you install additional packages if you need them.

Loop through checkboxes and count each one checked or unchecked

$.extend($.expr[':'], {
        unchecked: function (obj) {
            return ((obj.type == 'checkbox' || obj.type == 'radio') && !$(obj).is(':checked'));
        }
    });

$("input:checked")
$("input:unchecked")

Where is `%p` useful with printf?

The size of the pointer may be something different than that of int. Also an implementation could produce better than simple hex value representation of the address when you use %p.

AndroidStudio SDK directory does not exists

I finally find this file on the disk.The 'local.properties' file in The Android studio is not which you modify.see the picture,so you can modify this line 'sdk.dir' to your dir of sdk.Remember not in the android studio. enter image description here

How to open a website when a Button is clicked in Android application?

ImageView Button = (ImageView)findViewById(R.id.button);

Button.setOnClickListener(new OnClickListener() {

    public void onClick(View v) {
        Uri uri = Uri.parse("http://google.com/");

        Intent intent = new Intent(Intent.ACTION_VIEW, uri);
        startActivity(intent);
    }
});

Java Command line arguments

Command line arguments are stored as strings in the String array String[] args that is passed tomain()`.

java [program name] [arg1,arg2 ,..]

Command line arguments are the inputs that accept from the command prompt while running the program. The arguments passed can be anything. Which is stored in the args[] array.

//Display all command line information
         class ArgDemo{
            public static void main(String args[]){
            System.out.println("there are "+args.length+"command-line arguments.");
            for(int i=0;i<args.length;i++)
            System.out.println("args["+i+"]:"+args[i]);
    }
    }

Example:

java Argdemo one two

The output will be:

there are 2 command line arguments:
they are:
arg[0]:one
arg[1]:two

How to change folder with git bash?

The command is:

cd  /c/project/

Tip:
Use the pwd command to see which path you are currently in, handy when you did a right-click "Git Bash here..."

MySQL: Error dropping database (errno 13; errno 17; errno 39)

As for ERRORCODE 39, you can definately just delete the physical table files on the disk. the location depends on your OS distribution and setup. On Debian its typically under /var/lib/mysql/database_name/ So do a:

rm -f /var/lib/mysql/<database_name>/

And then drop the database from your tool of choice or using the command:

DROP DATABASE <database_name>

How to post a file from a form with Axios

This works for me, I hope helps to someone.

var frm = $('#frm');
let formData = new FormData(frm[0]);
axios.post('your-url', formData)
    .then(res => {
        console.log({res});
    }).catch(err => {
        console.error({err});
    });

How to set width of a div in percent in JavaScript?

Yes, it is:

<div id="myid">Some Content........</div>

document.getElementById('#myid').style.width = '50%';

How do I kill this tomcat process in Terminal?

ps -ef

will list all your currently running processes

| grep tomcat

will pass the output to grep and look for instances of tomcat. Since the grep is a process itself, it is returned from your command. However, your output shows no processes of Tomcat running.

A message body writer for Java type, class myPackage.B, and MIME media type, application/octet-stream, was not found

i was facing the same problem for a get method i was returning an "int" for the @get method Strangely when i change the return type to String the error was gone.Give it a try and if someone knows the logic behind it kindly share it

Is there a way to ignore a single FindBugs warning?

Here is a more complete example of an XML filter (the example above by itself will not work since it just shows a snippet and is missing the <FindBugsFilter> begin and end tags):

<FindBugsFilter>
    <Match>
        <Class name="com.mycompany.foo" />
        <Method name="bar" />
        <Bug pattern="NP_BOOLEAN_RETURN_NULL" />
    </Match>
</FindBugsFilter>

If you are using the Android Studio FindBugs plugin, browse to your XML filter file using File->Other Settings->Default Settings->Other Settings->FindBugs-IDEA->Filter->Exclude filter files->Add.

C# Creating and using Functions

static void Main(string[] args)
    {
        Console.WriteLine("geef een leeftijd");
        int a = Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("geef een leeftijd");
        int b = Convert.ToInt32(Console.ReadLine());

        int einde = Sum(a, b);
        Console.WriteLine(einde);
    }
    static int Sum(int x, int y)
    {
        int result = x + y;
        return result;

PHP error: "The zip extension and unzip command are both missing, skipping."

Actually composer nowadays seems to work without the zip command line command, so installing php-zip should be enough --- BUT it would display a warning:

As there is no 'unzip' command installed zip files are being unpacked using the PHP zip extension. This may cause invalid reports of corrupted archives. Installing 'unzip' may remediate them.

See also Is there a problem with using php-zip (composer warns about it)

Laravel Request getting current path with query string

Similar to Yada's answer: $request->url() will also work if you are injecting Illuminate\Http\Request

Edit: The difference between fullUrl and url is the fullUrl includes your query parameters

make image( not background img) in div repeat?

(DEMO)
Codes:

.backimage {width:99%;  height:98%;  position:absolute;    background:transparent url("http://upload.wikimedia.org/wikipedia/commons/4/41/Brickwall_texture.jpg") repeat scroll 0% 0%;  }

and

<div>
    <div class="backimage"></div>
    YOUR OTHER CONTENTTT
</div>

Is it possible to view RabbitMQ message contents directly from the command line?

You should enable the management plugin.

rabbitmq-plugins enable rabbitmq_management

See here:

http://www.rabbitmq.com/plugins.html

And here for the specifics of management.

http://www.rabbitmq.com/management.html

Finally once set up you will need to follow the instructions below to install and use the rabbitmqadmin tool. Which can be used to fully interact with the system. http://www.rabbitmq.com/management-cli.html

For example:

rabbitmqadmin get queue=<QueueName> requeue=false

will give you the first message off the queue.

LocalDate to java.util.Date and vice versa simplest conversion?

You can convert the java.util.Date object into a String object, which will format the date as yyyy-mm-dd.

LocalDate has a parse method that will convert it to a LocalDate object. The string must represent a valid date and is parsed using DateTimeFormatter.ISO_LOCAL_DATE.

Date to LocalDate

LocalDate.parse(Date.toString())

How to remove all white spaces in java

Replace all the spaces in the String with empty character.

String lineWithoutSpaces = line.replaceAll("\\s+","");

How to set all elements of an array to zero or any same value?

You could use memset, if you sure about the length.

memset(ptr, 0x00, length)

How to enable support of CPU virtualization on Macbook Pro?

Here is a way to check is virtualization is enabled or disabled by the firmware as suggested by this link in parallels.com.

How to check that Intel VT-x is supported in CPU:

  1. Open Terminal application from Application/Utilities

  2. Copy/paste command bellow

sysctl -a | grep machdep.cpu.features

  1. You may see output similar to:

Mac:~ user$ sysctl -a | grep machdep.cpu.features kern.exec: unknown type returned machdep.cpu.features: FPU VME DE PSE TSC MSR PAE MCE CX8 APIC SEP MTRR PGE MCA CMOV PAT CLFSH DS ACPI MMX FXSR SSE SSE2 SS HTT TM SSE3 MON VMX EST TM2 TPR PDCM

If you see VMX entry then CPU supports Intel VT-x feature, but it still may be disabled.

Refer to this link on Apple.com to enable hardware support for virtualization:

How can I get jQuery to perform a synchronous, rather than asynchronous, Ajax request?

Firstly we should understand when we use $.ajax and when we use $.get/$.post

When we require low level control over the ajax request such as request header settings, caching settings, synchronous settings etc.then we should go for $.ajax.

$.get/$.post: When we do not require low level control over the ajax request.Only simple get/post the data to the server.It is shorthand of

$.ajax({
  url: url,
  data: data,
  success: success,
  dataType: dataType
});

and hence we can not use other features(sync,cache etc.) with $.get/$.post.

Hence for low level control(sync,cache,etc.) over ajax request,we should go for $.ajax

 $.ajax({
     type: 'GET',
      url: url,
      data: data,
      success: success,
      dataType: dataType,
      async:false
    });

Run text file as commands in Bash

Execute

. example.txt

That does exactly what you ask for, without setting an executable flag on the file or running an extra bash instance.

For a detailed explanation see e.g. https://unix.stackexchange.com/questions/43882/what-is-the-difference-between-sourcing-or-source-and-executing-a-file-i

Session timeout in ASP.NET

if you are want session timeout for website than remove

<authentication mode="Forms">
      <forms timeout="50"/>
</authentication>

tag from web.config file.

How to make a script wait for a pressed key?

The python manual provides the following:

import termios, fcntl, sys, os
fd = sys.stdin.fileno()

oldterm = termios.tcgetattr(fd)
newattr = termios.tcgetattr(fd)
newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
termios.tcsetattr(fd, termios.TCSANOW, newattr)

oldflags = fcntl.fcntl(fd, fcntl.F_GETFL)
fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK)

try:
    while 1:
        try:
            c = sys.stdin.read(1)
            print "Got character", repr(c)
        except IOError: pass
finally:
    termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
    fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)

which can be rolled into your use case.

What does -> mean in C++?

member b of object pointed to by a a->b

Sorting Directory.GetFiles()

From msdn:

The order of the returned file names is not guaranteed; use the Sort() method if a specific sort order is required.

The Sort() method is the standard Array.Sort(), which takes in IComparables (among other overloads), so if you sort by creation date, it will handle localization based on the machine settings.

Editing dictionary values in a foreach loop

You are modifying the collection in this line:

colStates[key] = 0;

By doing so, you are essentially deleting and reinserting something at that point (as far as IEnumerable is concerned anyways.

If you edit a member of the value you are storing, that would be OK, but you are editing the value itself and IEnumberable doesn't like that.

The solution I've used is to eliminate the foreach loop and just use a for loop. A simple for loop won't check for changes that you know won't effect the collection.

Here's how you could do it:

List<string> keys = new List<string>(colStates.Keys);
for(int i = 0; i < keys.Count; i++)
{
    string key = keys[i];
    double  Percent = colStates[key] / TotalCount;
    if (Percent < 0.05)    
    {        
        OtherCount += colStates[key];
        colStates[key] = 0;    
    }
}

Android: How to get a custom View's height and width?

You can use the following method to get the width and height of the view, For example,

int height = yourView.getLayoutParams().height;
int width = yourView.getLayoutParams().width;

This gives the converted value of the view which specified in the XML layout.

Say if the specified value for height is 53dp in XML, you will get the converted value in integer as 80.

Accessing the index in 'for' loops?

According to this discussion: http://bytes.com/topic/python/answers/464012-objects-list-index

Loop counter iteration

The current idiom for looping over the indices makes use of the built-in range function:

for i in range(len(sequence)):
    # work with index i

Looping over both elements and indices can be achieved either by the old idiom or by using the new zip built-in function:

for i in range(len(sequence)):
    e = sequence[i]
    # work with index i and element e

or

for i, e in zip(range(len(sequence)), sequence):
    # work with index i and element e

via http://www.python.org/dev/peps/pep-0212/

Android layout replacing a view with another view on run time

it work in my case, oldSensor and newSnsor - oldView and newView:

private void replaceSensors(View oldSensor, View newSensor) {
            ViewGroup parent = (ViewGroup) oldSensor.getParent();

            if (parent == null) {
                return;
            }

            int indexOldSensor = parent.indexOfChild(oldSensor);
            int indexNewSensor = parent.indexOfChild(newSensor);
            parent.removeView(oldSensor);
            parent.addView(oldSensor, indexNewSensor);
            parent.removeView(newSensor);
            parent.addView(newSensor, indexOldSensor);
        }

Javascript: Load an Image from url and display

First, I strongly suggest to use a Library or Framework to do your Javascript. But just for something very very simple, or for the fun to learn, it is ok. (you can use jquery, underscore, knockoutjs, angular)

Second, it is not advised to bind directly to onclick, my first suggestion goes in that way too.

That's said What you need is to modify the src of a img in your page.

In the place where you want your image displayed, you should insert a img tag like this:

Next, you need to modify the onclick to update the src attribute. The easiest way I can think of is like his

onclick=""document.getElementById('image-placeholder').src = 'http://webpage.com/images/' + document.getElementById('imagename').value + '.png"

Then again, it is not the best way to do it, but it is a start. I recommend you to try jQuery and see how can you accomplish the same whitout using onclick (tip... check the section on jquery about events)

I did a simple fiddle as a example of your poblem using some google logos... type 4 o 3 in the box and you'll two images of different size. (sorry.. I have no time to search for better images as example)

http://jsfiddle.net/HsnSa/

How to overcome root domain CNAME restrictions?

I see readytocloud.com is hosted on Apache 2.2.

There is a much simpler and more efficient way to redirect the non-www site to the www site in Apache.

Add the following rewrite rules to the Apache configs (either inside the virtual host or outside. It doesn't matter):

RewriteCond %{HTTP_HOST} ^readytocloud.com [NC]
RewriteRule ^/$ http://www.readytocloud.com/ [R=301,L]

Or, the following rewrite rules if you want a 1-to-1 mapping of URLs from the non-www site to the www site:

RewriteCond %{HTTP_HOST} ^readytocloud.com [NC]
RewriteRule (.*) http://www.readytocloud.com$1 [R=301,L]

Note, the mod_rewrite module needs to be loaded for this to work. Luckily readytocloud.com is runing on a CentOS box, which by default loads mod_rewrite.

We have a client server running Apache 2.2 with just under 3,000 domains and nearly 4,000 redirects, however, the load on the server hover around 0.10 - 0.20.

Superscript in markdown (Github flavored)?

Comments about previous answers

The universal solution is using the HTML tag <sup>, as suggested in the main answer.
However, the idea behind Markdown is precisely to avoid the use of such tags:
The document should look nice as plain text, not only when rendered.

Another answer proposes using Unicode characters, which makes the document look nice as a plain text document but could reduce compatibility.

Finally, I would like to remember the simplest solution for some documents: the character ^.
Some Markdown implementation (e.g. MacDown in macOS) interprets the caret as an instruction for superscript.

Ex.
Sin^2 + Cos^2 = 1
Clearly, Stack Overflow does not interpret the caret as a superscript instruction. However, the text is comprehensible, and this is what really matters when using Markdown.

How to prevent "The play() request was interrupted by a call to pause()" error?

I have used a trick to counter this issue. Define a global variable var audio;

and in the function check

if(audio === undefined)
{
   audio = new Audio(url);
}

and in the stop function

audio.pause();
audio = undefined;

so the next call of audio.play, audio will be ready from '0' currentTime

I used

audio.pause();
audio.currentTime =0.0; 

but it didn't work. Thanks.

Is it possible to get a history of queries made in postgres

You can use like

\s 

it will fetch you all command history of the terminal, to export it to file using

\s filename

Run CSS3 animation only once (at page loading)

After hours of googling: No, it's not possible without JavaScript. The animation-iteration-count: 1; is internally saved in the animation shothand attribute, which gets resetted and overwritten on :hover. When we blur the <a> and release the :hover the old class reapplies and therefore again resets the animation attribute.

There sadly is no way to save a certain attribute states across element states.

You'll have to use JavaScript.

How do I use StringUtils in Java?

StringUtils is an Apache Commons project. You need to download and add the library to your classpath.

To use:

import org.apache.commons.lang3.StringUtils;

Unable to access JSON property with "-" dash

For ansible, and using hyphen, this worked for me:

    - name: free-ud-ssd-space-in-percent
      debug:
        var: clusterInfo.json.content["free-ud-ssd-space-in-percent"]

How do I add a newline to a windows-forms TextBox?

make sure you textbox is set for multiline then you wont need any extra dims vbnewline will work just fine

difference between new String[]{} and new String[] in java

You have a choice, when you create an object array (as opposed to an array of primitives).

One option is to specify a size for the array, in which case it will just contain lots of nulls.

String[] array = new String[10]; // Array of size 10, filled with nulls.

The other option is to specify what will be in the array.

String[] array = new String[] {"Larry", "Curly", "Moe"};  // Array of size 3, filled with stooges.

But you can't mix the two syntaxes. Pick one or the other.

ActionController::InvalidAuthenticityToken

Problem solved by downgrading to 2.3.5 from 2.3.8. (as well as infamous 'You are being redirected.' issue)

ModalPopupExtender OK Button click event not firing?

None of the previous answers worked for me. I called the postback of the button on the OnOkScript event.

<div>
    <cc1:ModalPopupExtender PopupControlID="Panel1" 
         ID="ModalPopupExtender1"
         runat="server" TargetControlID="LinkButton1" OkControlID="Ok" 
         OnOkScript="__doPostBack('Ok','')">
    </cc1:ModalPopupExtender>

    <asp:LinkButton ID="LinkButton1" runat="server">LinkButton</asp:LinkButton> 
</div>        


<asp:Panel ID="Panel1" runat="server">
    <asp:Button ID="Ok" runat="server" Text="Ok" onclick="Ok_Click" />            
</asp:Panel>   

How to automatically insert a blank row after a group of data

Figured it out.

Step 1

Put a new column to the left of column1 and copy+paste the following formula

=B2=B3

=B3=B4

=B4=B5

... all the way to the bottom (assume column B here is column1 in the original question).

This formula evaluates whether or not the next row is a new value in column1. Deopending on the result, you will have TRUE or FALSE. Copy and Paste these results as values and then swap "FALSE" for nil and "TRUE" for 0.5

Step 2

Then add that column full of only 0.5's to the column1 which will yield the following table:

  newcolumn0  |   column1 ("B") |   column2   |  column3
-----------------------------------------------------
              |     1           |     small   |  blue
              |     1           |     small   |  orange
      1.5     |     1           |     small   |  yellow
              |     2           |     med     |  yellow
      2.5     |     2           |     med     |  blue
      3.5     |     3           |     large   |  green
              |     4           |     large   |  green
      4.5     |     4           |     small   |  pink

Step 3

Lastly, copy and paste the values from newcolumn0 right below the values in column1 and then sort the table by column1 and you should have a blank row in between each distinct whole number in column1, with the table something like this:

    newcolumn0   |  column1 ("B")  |   column2       |  column3
---------------------------------------------------------------
                 |     1           |     small   |  blue
                 |     1           |     small   |  orange
        1.5      |     1.5         |             |
                 |     1           |     small   |  yellow
                 |     2           |     med     |  yellow
                 |     2           |     med     |  blue
        2.5      |     2.5         |             |
                 |     3           |     large   |  green
        3.5      |     3.5         |             |
                 |     4           |     large   |  green
                 |     4           |     small   |  pink
        4.5      |     4.5         |             |

Alternative Solutions (still no VBA)

  1. Put a value of 1 Column 1, Row 2 (assume this is A2)
  2. Put this formula in A3 =IF(B3=B2,A2,A2+1) and copy+paste this formula for the rest of column 2
  3. Then copy and paste all the values from column 1 into a new temp excel sheet, remove duplicates, then add 0.5 to all numbers, then paste these values below the values in original spreadsheet below the data in column 1, paste all data in column as values and then sort by that column, delete the temp excel sheet

How do you add an image?

Just to clarify the problem here - the error is in the following bit of code:

<xsl:attribute name="src">
    <xsl:copy-of select="/root/Image/node()"/>
</xsl:attribute>

The instruction xsl:copy-of takes a node or node-set and makes a copy of it - outputting a node or node-set. However an attribute cannot contain a node, only a textual value, so xsl:value-of would be a possible solution (as this returns the textual value of a node or nodeset).

A MUCH shorter solution (and perhaps more elegant) would be the following:

<img width="100" height="100" src="{/root/Image/node()}" class="CalloutRightPhoto"/>

The use of the {} in the attribute is called an Attribute Value Template, and can contain any XPATH expression.

Note, the same XPath can be used here as you have used in the xsl_copy-of as it knows to take the textual value when used in a Attribute Value Template.

Getter and Setter declaration in .NET

With this, you can perform some code in the get or set scope.

private string _myProperty;
public string myProperty
{
    get { return _myProperty; }
    set { _myProperty = value; }
}

You also can use automatic properties:

public string myProperty
{
    get;
    set;
}

And .Net Framework will manage for you. It was create because it is a good pratice and make it easy to do.

You also can control the visibility of these scopes, for sample:

public string myProperty
{
    get;
    private set;
}

public string myProperty2
{
    get;
    protected set;
}

public string myProperty3
{
    get; 
}

Update

Now in C# you can initialize the value of a property. For sample:

public int Property { get; set; } = 1;

If also can define it and make it readonly, without a set.

public int Property { get; } = 1;

And finally, you can define an arrow function.

public int Property => GetValue();

Finding and removing non ascii characters from an Oracle Varchar2

If you use the ASCIISTR function to convert the Unicode to literals of the form \nnnn, you can then use REGEXP_REPLACE to strip those literals out, like so...

UPDATE table SET field = REGEXP_REPLACE(ASCIISTR(field), '\\[[:xdigit:]]{4}', '')

...where field and table are your field and table names respectively.

Convert JSON to Map

If you're using org.json, JSONObject has a method toMap(). You can easily do:

Map<String, Object> myMap = myJsonObject.toMap();

.datepicker('setdate') issues, in jQuery

If you would like to support really old browsers you should parse the date string, since using the ISO8601 date format with the Date constructor is not supported pre IE9:

var queryDate = '2009-11-01',
    dateParts = queryDate.match(/(\d+)/g)
    realDate = new Date(dateParts[0], dateParts[1] - 1, dateParts[2]);  
                                    // months are 0-based!
// For >= IE9
var realDate = new Date('2009-11-01');  

$('#datePicker').datepicker({ dateFormat: 'yy-mm-dd' }); // format to show
$('#datePicker').datepicker('setDate', realDate);

Check the above example here.

How to find SQL Server running port?

very simple. make a note of the sqlsrvr.exe PID from taskmanager then run this command:

netstat -ano | findstr *PID*

it will show TCP and UDP connections of your SQL server (including ports) standard is 1433 for TCP and 1434 for UDP

example : enter image description here

Using both Python 2.x and Python 3.x in IPython Notebook

Use sudo pip3 install jupyter for installing jupyter for python3 and sudo pip install jupyter for installing jupyter notebook for python2. Then, you can call ipython kernel install command to enable both types of notebook to choose from in jupyter notebook.

Javascript Debugging line by line using Google Chrome

...How can I step through my javascript code line by line using Google Chromes developer tools without it going into javascript libraries?...


For the record: At this time (Feb/2015) both Google Chrome and Firefox have exactly what you (and I) need to avoid going inside libraries and scripts, and go beyond the code that we are interested, It's called Black Boxing:

enter image description here

When you blackbox a source file, the debugger will not jump into that file when stepping through code you're debugging.

More info:

Jenkins not executing jobs (pending - waiting for next executor)

The Jenkins admin console can run, even with the Master node offline. This can happen when Jenkins runs out of disk space.

To confirm, do the following (with thanks to geekride - jenkins-pending-waiting-for-next-available-executor):

  • go to Jenkins -> Manage Jenkins -> Manage Nodes
  • examine the "master" node to see if it is offline. It may be reporting that the master node is out of disk space.

How to check if the request is an AJAX request with PHP

From PHP 7 with null coalescing operator it will be shorter:

$is_ajax = 'xmlhttprequest' == strtolower( $_SERVER['HTTP_X_REQUESTED_WITH'] ?? '' );

How can I clear the SQL Server query cache?

Here is some good explaination. check out it.

http://www.mssqltips.com/tip.asp?tip=1360

CHECKPOINT; 
GO 
DBCC DROPCLEANBUFFERS; 
GO

From the linked article:

If all of the performance testing is conducted in SQL Server the best approach may be to issue a CHECKPOINT and then issue the DBCC DROPCLEANBUFFERS command. Although the CHECKPOINT process is an automatic internal system process in SQL Server and occurs on a regular basis, it is important to issue this command to write all of the dirty pages for the current database to disk and clean the buffers. Then the DBCC DROPCLEANBUFFERS command can be executed to remove all buffers from the buffer pool.

Multiple markers Google Map API v3 from array of addresses and avoid OVER_QUERY_LIMIT while geocoding on pageLoad

Regardless of your situation, heres a working demo that creates markers on the map based on an array of addresses.

http://jsfiddle.net/P2QhE/

Javascript code embedded aswell:

$(document).ready(function () {
    var map;
    var elevator;
    var myOptions = {
        zoom: 1,
        center: new google.maps.LatLng(0, 0),
        mapTypeId: 'terrain'
    };
    map = new google.maps.Map($('#map_canvas')[0], myOptions);

    var addresses = ['Norway', 'Africa', 'Asia','North America','South America'];

    for (var x = 0; x < addresses.length; x++) {
        $.getJSON('http://maps.googleapis.com/maps/api/geocode/json?address='+addresses[x]+'&sensor=false', null, function (data) {
            var p = data.results[0].geometry.location
            var latlng = new google.maps.LatLng(p.lat, p.lng);
            new google.maps.Marker({
                position: latlng,
                map: map
            });

        });
    }

}); 

find index of an int in a list

Use the .IndexOf() method of the list. Specs for the method can be found on MSDN.

nano error: Error opening terminal: xterm-256color

  1. edit your .bash_profile file

    vim .bash_profile

  2. commnet

    #export TERM=xterm-256color

  3. add this

    export TERMINFO=/usr/share/terminfo

    export TERM=xterm-basic

    to your .bash_profile

  4. finally

    run:

    source .bash_profile

Splitting a table cell into two columns in HTML

Use this example, you can split with the colspan attribute

<TABLE BORDER>
     <TR>
         <TD>Item 1</TD>
         <TD>Item 1</TD>
         <TD COLSPAN=2>Item 2</TD>
    </TR>
    <TR>
         <TD>Item 3</TD>
         <TD>Item 3</TD>
         <TD>Item 4</TD>
         <TD>Item 5</TD>
    </TR>
</TABLE>

More examples at http://hypermedia.univ-paris8.fr/jean/internet/ex_table.html.

How to adjust the size of y axis labels only in R?

ucfagls is right, providing you use the plot() command. If not, please give us more detail.

In any case, you can control every axis seperately by using the axis() command and the xaxt/yaxt options in plot(). Using the data of ucfagls, this becomes :

plot(Y ~ X, data=foo,yaxt="n")
axis(2,cex.axis=2)

the option yaxt="n" is necessary to avoid that the plot command plots the y-axis without changing. For the x-axis, this works exactly the same :

plot(Y ~ X, data=foo,xaxt="n")
axis(1,cex.axis=2)

See also the help files ?par and ?axis


Edit : as it is for a barplot, look at the options cex.axis and cex.names :

tN <- table(sample(letters[1:5],100,replace=T,p=c(0.2,0.1,0.3,0.2,0.2)))

op <- par(mfrow=c(1,2))
barplot(tN, col=rainbow(5),cex.axis=0.5) # for the Y-axis
barplot(tN, col=rainbow(5),cex.names=0.5) # for the X-axis
par(op)

alt text

Difference between volatile and synchronized in Java

It's important to understand that there are two aspects to thread safety.

  1. execution control, and
  2. memory visibility

The first has to do with controlling when code executes (including the order in which instructions are executed) and whether it can execute concurrently, and the second to do with when the effects in memory of what has been done are visible to other threads. Because each CPU has several levels of cache between it and main memory, threads running on different CPUs or cores can see "memory" differently at any given moment in time because threads are permitted to obtain and work on private copies of main memory.

Using synchronized prevents any other thread from obtaining the monitor (or lock) for the same object, thereby preventing all code blocks protected by synchronization on the same object from executing concurrently. Synchronization also creates a "happens-before" memory barrier, causing a memory visibility constraint such that anything done up to the point some thread releases a lock appears to another thread subsequently acquiring the same lock to have happened before it acquired the lock. In practical terms, on current hardware, this typically causes flushing of the CPU caches when a monitor is acquired and writes to main memory when it is released, both of which are (relatively) expensive.

Using volatile, on the other hand, forces all accesses (read or write) to the volatile variable to occur to main memory, effectively keeping the volatile variable out of CPU caches. This can be useful for some actions where it is simply required that visibility of the variable be correct and order of accesses is not important. Using volatile also changes treatment of long and double to require accesses to them to be atomic; on some (older) hardware this might require locks, though not on modern 64 bit hardware. Under the new (JSR-133) memory model for Java 5+, the semantics of volatile have been strengthened to be almost as strong as synchronized with respect to memory visibility and instruction ordering (see http://www.cs.umd.edu/users/pugh/java/memoryModel/jsr-133-faq.html#volatile). For the purposes of visibility, each access to a volatile field acts like half a synchronization.

Under the new memory model, it is still true that volatile variables cannot be reordered with each other. The difference is that it is now no longer so easy to reorder normal field accesses around them. Writing to a volatile field has the same memory effect as a monitor release, and reading from a volatile field has the same memory effect as a monitor acquire. In effect, because the new memory model places stricter constraints on reordering of volatile field accesses with other field accesses, volatile or not, anything that was visible to thread A when it writes to volatile field f becomes visible to thread B when it reads f.

-- JSR 133 (Java Memory Model) FAQ

So, now both forms of memory barrier (under the current JMM) cause an instruction re-ordering barrier which prevents the compiler or run-time from re-ordering instructions across the barrier. In the old JMM, volatile did not prevent re-ordering. This can be important, because apart from memory barriers the only limitation imposed is that, for any particular thread, the net effect of the code is the same as it would be if the instructions were executed in precisely the order in which they appear in the source.

One use of volatile is for a shared but immutable object is recreated on the fly, with many other threads taking a reference to the object at a particular point in their execution cycle. One needs the other threads to begin using the recreated object once it is published, but does not need the additional overhead of full synchronization and it's attendant contention and cache flushing.

// Declaration
public class SharedLocation {
    static public SomeObject someObject=new SomeObject(); // default object
    }

// Publishing code
// Note: do not simply use SharedLocation.someObject.xxx(), since although
//       someObject will be internally consistent for xxx(), a subsequent 
//       call to yyy() might be inconsistent with xxx() if the object was 
//       replaced in between calls.
SharedLocation.someObject=new SomeObject(...); // new object is published

// Using code
private String getError() {
    SomeObject myCopy=SharedLocation.someObject; // gets current copy
    ...
    int cod=myCopy.getErrorCode();
    String txt=myCopy.getErrorText();
    return (cod+" - "+txt);
    }
// And so on, with myCopy always in a consistent state within and across calls
// Eventually we will return to the code that gets the current SomeObject.

Speaking to your read-update-write question, specifically. Consider the following unsafe code:

public void updateCounter() {
    if(counter==1000) { counter=0; }
    else              { counter++; }
    }

Now, with the updateCounter() method unsynchronized, two threads may enter it at the same time. Among the many permutations of what could happen, one is that thread-1 does the test for counter==1000 and finds it true and is then suspended. Then thread-2 does the same test and also sees it true and is suspended. Then thread-1 resumes and sets counter to 0. Then thread-2 resumes and again sets counter to 0 because it missed the update from thread-1. This can also happen even if thread switching does not occur as I have described, but simply because two different cached copies of counter were present in two different CPU cores and the threads each ran on a separate core. For that matter, one thread could have counter at one value and the other could have counter at some entirely different value just because of caching.

What's important in this example is that the variable counter was read from main memory into cache, updated in cache and only written back to main memory at some indeterminate point later when a memory barrier occurred or when the cache memory was needed for something else. Making the counter volatile is insufficient for thread-safety of this code, because the test for the maximum and the assignments are discrete operations, including the increment which is a set of non-atomic read+increment+write machine instructions, something like:

MOV EAX,counter
INC EAX
MOV counter,EAX

Volatile variables are useful only when all operations performed on them are "atomic", such as my example where a reference to a fully formed object is only read or written (and, indeed, typically it's only written from a single point). Another example would be a volatile array reference backing a copy-on-write list, provided the array was only read by first taking a local copy of the reference to it.

Using fonts with Rails asset pipeline

In my case the original question was using asset-url without results instead of plain url css property. Using asset-url ended up working for me in Heroku. Plus setting the fonts in /assets/fonts folder and calling asset-url('font.eot') without adding any subfolder or any other configuration to it.

Can an html element have multiple ids?

http://www.w3.org/TR/REC-html40/struct/global.html#h-7.5.2

The id attribute assigns a unique identifier to an element (which may be verified by an SGML parser).

and

ID and NAME tokens must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods (".").

So "id" must be unique and can't contain a space.

PHP append one array to another (not array_push or +)

It's a pretty old post, but I want to add something about appending one array to another:

If

  • one or both arrays have associative keys
  • the keys of both arrays don't matter

you can use array functions like this:

array_merge(array_values($array), array_values($appendArray));

array_merge doesn't merge numeric keys so it appends all values of $appendArray. While using native php functions instead of a foreach-loop, it should be faster on arrays with a lot of elements.

Addition 2019-12-13: Since PHP 7.4, there is the possibility to append or prepend arrays the Array Spread Operator way:

    $a = [3, 4];
    $b = [1, 2, ...$a];

As before, keys can be an issue with this new feature:

    $a = ['a' => 3, 'b' => 4];
    $b = ['c' => 1, 'a' => 2, ...$a];

"Fatal error: Uncaught Error: Cannot unpack array with string keys"

    $a = [3 => 3, 4 => 4];
    $b = [1 => 1, 4 => 2, ...$a];

array(4) { [1]=> int(1) [4]=> int(2) [5]=> int(3) [6]=> int(4) }

    $a = [1 => 1, 2 => 2];
    $b = [...$a, 3 => 3, 1 => 4];

array(3) { [0]=> int(1) [1]=> int(4) [3]=> int(3) }

Determine if an element has a CSS class with jQuery

Use the hasClass method:

jQueryCollection.hasClass(className);

or

$(selector).hasClass(className);

The argument is (obviously) a string representing the class you are checking, and it returns a boolean (so it doesn't support chaining like most jQuery methods).

Note: If you pass a className argument that contains whitespace, it will be matched literally against the collection's elements' className string. So if, for instance, you have an element,

<span class="foo bar" />

then this will return true:

$('span').hasClass('foo bar')

and these will return false:

$('span').hasClass('bar foo')
$('span').hasClass('foo  bar')

EditText, inputType values (xml)

You can use the properties tab in eclipse to set various values.

here are all the possible values

  • none
  • text
  • textCapCharacters
  • textCapWords
  • textCapSentences
  • textAutoCorrect
  • textAutoComplete
  • textMultiLine
  • textImeMultiLine
  • textNoSuggestions
  • textUri
  • textEmailAddress
  • textEmailSubject
  • textShortMessage
  • textLongMessage
  • textPersonName
  • textPostalAddress
  • textPassword
  • textVisiblePassword
  • textWebEditText
  • textFilter
  • textPhonetic
  • textWebEmailAddress
  • textWebPassword
  • number
  • numberSigned
  • numberDecimal
  • numberPassword
  • phone
  • datetime
  • date
  • time

Check here for explanations: http://developer.android.com/reference/android/widget/TextView.html#attr_android:inputType

php date validation

Nicolas solution is best. If you want in regex,

try this,

this will validate for, 01/01/1900 through 12/31/2099 Matches invalid dates such as February 31st Accepts dashes, spaces, forward slashes and dots as date separators

(0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])[- /.](19|20)[0-9]{2}

Automapper missing type map configuration or unsupported mapping - Error

In my case, I had created the map, but was missing the ReverseMap function. Adding it got rid of the error.

      private static void RegisterServices(ContainerBuilder bldr)
      {
         var config = new MapperConfiguration(cfg =>
         {
            cfg.AddProfile(new CampMappingProfile());
         });
         ...
       }


      public CampMappingProfile()
      {
         CreateMap<Talk, TalkModel>().ReverseMap();
         ...
      }

How to generate List<String> from SQL query?

Where the data returned is a string; you could cast to a different data type:

(from DataRow row in dataTable.Rows select row["columnName"].ToString()).ToList();

Is there a max array length limit in C++?

There are two limits, both not enforced by C++ but rather by the hardware.

The first limit (should never be reached) is set by the restrictions of the size type used to describe an index in the array (and the size thereof). It is given by the maximum value the system's std::size_t can take. This data type is large enough to contain the size in bytes of any object

The other limit is a physical memory limit. The larger your objects in the array are, the sooner this limit is reached because memory is full. For example, a vector<int> of a given size n typically takes multiple times as much memory as an array of type vector<char> (minus a small constant value), since int is usually bigger than char. Therefore, a vector<char> may contain more items than a vector<int> before memory is full. The same counts for raw C-style arrays like int[] and char[].

Additionally, this upper limit may be influenced by the type of allocator used to construct the vector because an allocator is free to manage memory any way it wants. A very odd but nontheless conceivable allocator could pool memory in such a way that identical instances of an object share resources. This way, you could insert a lot of identical objects into a container that would otherwise use up all the available memory.

Apart from that, C++ doesn't enforce any limits.

How do I remove the blue styling of telephone numbers on iPhone/iOS?

If you don't intend to have any telephone numbers on your page, then <meta name="format-detection" content="telephone=no"> will work just fine. But rhetorically speaking, what if you intend to use a mix of phone and non-phone numbers?

Assuming you're just hard-coding numbers into your HTML, the "insert stuff in the middle of your digits" hacks will work. But they are of little to no use for dynamic pages, such as using PHP to output numerical data from a query.

As an example, I was generating a list of city populations. Some of the populations were large enough to cause Mobile Safari to turn them into phone number links. Fortunately, all I had to do was use PHP number_format() around the array output to insert "thousands" commas:

<?php echo number_format($row["population"]) ?>

This formatting was enough to convince Mobile Safari that there was a somewhat more specific purpose for the number, so it didn't default my larger numbers into telephone links anymore. The same would hold true for the suggestion by @davidcondrey of using <a href="tel:18001234567">1-800-123-4567</a> to specify a purpose to the number.

Bottom line is that Safari Mobile apparently does pay attention to semantics. Given that HTML5 is built around semantic markup, and search engines are relying on semantic markup, I intend to use it as much as I can.

How to update the value of a key in a dictionary in Python?

n = eval(input('Num books: '))
books = {}
for i in range(n):
    titlez = input("Enter Title: ")
    copy = eval(input("Num of copies: "))
    books[titlez] = copy

prob = input('Sell a book; enter YES or NO: ')
if prob == 'YES' or 'yes':
    choice = input('Enter book title: ')
    if choice in books:
        init_num = books[choice]
        init_num -= 1
        books[choice] = init_num
        print(books)

increase the java heap size permanently?

For Windows users, you can add a system environment variable named _JAVA_OPTIONS, and set the heap size values there. The JVM should be able to grab the virtual machine options from _JAVA_OPTIONS.

How do I change Eclipse to use spaces instead of tabs?

In eclipse mars (EE) on Mac OS X, the only way I could find this in the preferences was to open the Preference dialog and type Formatter, then select Java->Code Style->Formatter.

Java->Code Style has no access to Formatter!

ToggleButton in C# WinForms

How about this?

Assuming you have System.Windows.Forms referenced.

var cbtnToggler = new CheckBox();
cbtnToggler.Appearance = Appearance.Button;
cbtnToggler.TextAlign = ContentAlignment.MiddleCenter;
cbtnToggler.MinimumSize = new Size(75, 25); //To prevent shrinkage!

Hope this helps ;)

Getting a 500 Internal Server Error on Laravel 5+ Ubuntu 14.04

Run these two commands on root of laravel

find * -type d -print0 | xargs -0 chmod 0755 # for directories

find . -type f -print0 | xargs -0 chmod 0644 # for files

Insert a line at specific line number with sed or awk

POSIX sed (and for example OS X's sed, the sed below) require i to be followed by a backslash and a newline. Also at least OS X's sed does not include a newline after the inserted text:

$ seq 3|gsed '2i1.5'
1
1.5
2
3
$ seq 3|sed '2i1.5'
sed: 1: "2i1.5": command i expects \ followed by text
$ seq 3|sed $'2i\\\n1.5'
1
1.52
3
$ seq 3|sed $'2i\\\n1.5\n'
1
1.5
2
3

To replace a line, you can use the c (change) or s (substitute) commands with a numeric address:

$ seq 3|sed $'2c\\\n1.5\n'
1
1.5
3
$ seq 3|gsed '2c1.5'
1
1.5
3
$ seq 3|sed '2s/.*/1.5/'
1
1.5
3

Alternatives using awk:

$ seq 3|awk 'NR==2{print 1.5}1'
1
1.5
2
3
$ seq 3|awk '{print NR==2?1.5:$0}'
1
1.5
3

awk interprets backslashes in variables passed with -v but not in variables passed using ENVIRON:

$ seq 3|awk -v v='a\ba' '{print NR==2?v:$0}'
1
a
3
$ seq 3|v='a\ba' awk '{print NR==2?ENVIRON["v"]:$0}'
1
a\ba
3

Both ENVIRON and -v are defined by POSIX.

How to get a subset of a javascript object's properties

Good-old Array.prototype.reduce:

const selectable = {a: null, b: null};
const v = {a: true, b: 'yes', c: 4};

const r = Object.keys(selectable).reduce((a, b) => {
  return (a[b] = v[b]), a;
}, {});

console.log(r);

this answer uses the magical comma-operator, also: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comma_Operator

if you want to get really fancy, this is more compact:

const r = Object.keys(selectable).reduce((a, b) => (a[b] = v[b], a), {});

Putting it all together into a reusable function:

const getSelectable = function (selectable, original) {
  return Object.keys(selectable).reduce((a, b) => (a[b] = original[b], a), {})
};

const r = getSelectable(selectable, v);
console.log(r);

setTimeout / clearTimeout problems

The problem is that the timer variable is local, and its value is lost after each function call.

You need to persist it, you can put it outside the function, or if you don't want to expose the variable as global, you can store it in a closure, e.g.:

var endAndStartTimer = (function () {
  var timer; // variable persisted here
  return function () {
    window.clearTimeout(timer);
    //var millisecBeforeRedirect = 10000; 
    timer = window.setTimeout(function(){alert('Hello!');},10000); 
  };
})();

Reverse Y-Axis in PyPlot

Use matplotlib.pyplot.axis()

axis([xmin, xmax, ymin, ymax])

So you could add something like this at the end:

plt.axis([min(x_arr), max(x_arr), max(y_arr), 0])

Although you might want padding at each end so that the extreme points don't sit on the border.

Java out.println() how is this possible?

PrintStream out = System.out;
out.println( "hello" );

How to locate the Path of the current project directory in Java (IDE)?

File currDir = new File(".");
String path = currDir.getAbsolutePath();
System.out.println(path);

This will print . at the end. To remove, simply truncate the string by one char e.g.:

File currDir = new File(".");
String path = currDir.getAbsolutePath();
path = path.substring(0, path.length()-1);
System.out.println(path);

What are the proper permissions for an upload folder with PHP/Apache?

Remember also CHOWN or chgrp your website folder. Try myusername# chown -R myusername:_www uploads

Rename multiple files in cmd

for /f "delims=" %%i in ('dir /b /a-d *.txt') do ren "%%~i" "%%~ni 1.1%%~xi"

If you use the simple for loop without the /f parameter, already renamed files will be again renamed.

Writing Python lists to columns in csv

I just wanted to add to this one- because quite frankly, I banged my head against it for a while - and while very new to python - perhaps it will help someone else out.

 writer.writerow(("ColName1", "ColName2", "ColName"))
                 for i in range(len(first_col_list)):
                     writer.writerow((first_col_list[i], second_col_list[i], third_col_list[i]))

Avoid "current URL string parser is deprecated" warning by setting useNewUrlParser to true

If username or password has the @ character, then use it like this:

mongoose
    .connect(
        'DB_url',
        { user: '@dmin', pass: 'p@ssword', useNewUrlParser: true }
    )
    .then(() => console.log('Connected to MongoDB'))
    .catch(err => console.log('Could not connect to MongoDB', err));

Fast way to get the min/max values among properties of object

min and max have to loop through the input array anyway - how else would they find the biggest or smallest element?

So just a quick for..in loop will work just fine.

var min = Infinity, max = -Infinity, x;
for( x in input) {
    if( input[x] < min) min = input[x];
    if( input[x] > max) max = input[x];
}

C++ float array initialization

You only initialize the first N positions to the values in braces and all others are initialized to 0. In this case, N is the number of arguments you passed to the initialization list, i.e.,

float arr1[10] = { };       // all elements are 0
float arr2[10] = { 0 };     // all elements are 0
float arr3[10] = { 1 };     // first element is 1, all others are 0
float arr4[10] = { 1, 2 };  // first element is 1, second is 2, all others are 0

Ordering issue with date values when creating pivot tables

I saw this somewhere else. I am using 2016 Excel. What worked for me was to use YYYY Quarters (I was looking for quarterly data). So, I had the source data sorted as YYYY xQ. 2016 1Q, 2016 2Q, 2016 3Q, 2016, 4Q, 2017 1Q, 2017 2Q... You get the idea.

How do I install Composer on a shared hosting?

It depends on the host, but you probably simply can't (you can't on my shared host on Rackspace Cloud Sites - I asked them).

What you can do is set up an environment on your dev machine that roughly matches your shared host, and do all of your management through the command line locally. Then when everything is set (you've pulled in all the dependencies, updated, managed with git, etc.) you can "push" that to your shared host over (s)FTP.

How do I configure Maven for offline development?

Maven needs the dependencies in your local repository. The easiest way to get them is with internet access (or harder using other solutions provided here).

So assumed that you can get temporarily internet access you can prepare to go offline using the maven-dependency-plugin with its dependency:go-offline goal. This will download all your project dependencies to your local repository (of course changes in the dependencies / plugins will require new internet / central repository access).

How to change the minSdkVersion of a project?

Delete this line:

<uses-sdk android:targetSdkVersion="..." />

in the file:

AndroidManifest.xml

Get HTML5 localStorage keys

You can get keys and values like this:

for (let [key, value] of Object.entries(localStorage)) {
  console.log(`${key}: ${value}`);
}

Deserialize JSON with Jackson into Polymorphic Types - A Complete Example is giving me a compile error

Handling polymorphism is either model-bound or requires lots of code with various custom deserializers. I'm a co-author of a JSON Dynamic Deserialization Library that allows for model-independent json deserialization library. The solution to OP's problem can be found below. Note that the rules are declared in a very brief manner.

public class SOAnswer {
    @ToString @Getter @Setter
    @AllArgsConstructor @NoArgsConstructor
    public static abstract class Animal {
        private String name;    
    }

    @ToString(callSuper = true) @Getter @Setter
    @AllArgsConstructor @NoArgsConstructor
    public static class Dog extends Animal {
        private String breed;
    }

    @ToString(callSuper = true) @Getter @Setter
    @AllArgsConstructor @NoArgsConstructor
    public static class Cat extends Animal {
        private String favoriteToy;
    }
    
    
    public static void main(String[] args) {
        String json = "[{"
                + "    \"name\": \"pluto\","
                + "    \"breed\": \"dalmatian\""
                + "},{"
                + "    \"name\": \"whiskers\","
                + "    \"favoriteToy\": \"mouse\""
                + "}]";
        
        // create a deserializer instance
        DynamicObjectDeserializer deserializer = new DynamicObjectDeserializer();
        
        // runtime-configure deserialization rules; 
        // condition is bound to the existence of a field, but it could be any Predicate
        deserializer.addRule(DeserializationRuleFactory.newRule(1, 
                (e) -> e.getJsonNode().has("breed"),
                DeserializationActionFactory.objectToType(Dog.class)));
        
        deserializer.addRule(DeserializationRuleFactory.newRule(1, 
                (e) -> e.getJsonNode().has("favoriteToy"),
                DeserializationActionFactory.objectToType(Cat.class)));
        
        List<Animal> deserializedAnimals = deserializer.deserializeArray(json, Animal.class);
        
        for (Animal animal : deserializedAnimals) {
            System.out.println("Deserialized Animal Class: " + animal.getClass().getSimpleName()+";\t value: "+animal.toString());
        }
    }
}

Maven depenendency for pretius-jddl (check newest version at maven.org/jddl:

<dependency>
  <groupId>com.pretius</groupId>
  <artifactId>jddl</artifactId>
  <version>1.0.0</version>
</dependency>

Android Studio: /dev/kvm device permission denied

This is because /dev/kvm is not accessible. To make is accessible from android studio run the below command

sudo chmod 777 -R /dev/kvm

It will ask for your password. After that restart Android Studio.

KVM is required to rum emulator. If you have not install it yet then install it

sudo apt install qemu-kvm

MySQL - Rows to Columns

My solution :

select h.hostid, sum(ifnull(h.A,0)) as A, sum(ifnull(h.B,0)) as B, sum(ifnull(h.C,0)) as  C from (
select
hostid,
case when itemName = 'A' then itemvalue end as A,
case when itemName = 'B' then itemvalue end as B,
case when itemName = 'C' then itemvalue end as C
  from history 
) h group by hostid

It produces the expected results in the submitted case.

How do I wrap text in a span?

Try putting your text in another div inside your span:

i.e.

<span><div>some text</div></span>

How to setup Main class in manifest file in jar produced by NetBeans project

In 7.3 just enable Properties/Build/Package/Copy Dependent Libraries and main class will be added to manifest when building depending on selected target.

Replace characters from a column of a data frame R

You can use the stringr library:

library('stringr')

a <- runif(10)
b <- letters[1:10]
c <- c(rep('A-B', 4), rep('A_B', 6))
data <- data.frame(a, b, c)

data

#             a b   c
# 1  0.19426707 a A-B
# 2  0.12902673 b A-B
# 3  0.78324955 c A-B
# 4  0.06469028 d A-B
# 5  0.34752264 e A_C
# 6  0.55313288 f A_C
# 7  0.31264280 g A_C
# 8  0.33759921 h A_C
# 9  0.72322599 i A_C
# 10 0.25223075 j A_C

data$c <- str_replace_all(data$c, '_', '-')

data

#             a b   c
# 1  0.19426707 a A-B
# 2  0.12902673 b A-B
# 3  0.78324955 c A-B
# 4  0.06469028 d A-B
# 5  0.34752264 e A-C
# 6  0.55313288 f A-C
# 7  0.31264280 g A-C
# 8  0.33759921 h A-C
# 9  0.72322599 i A-C
# 10 0.25223075 j A-C

Note that this does change factored variables into character.

How to create Android Facebook Key Hash?

step 1->open cmd in your system

step 2->C:\Program Files\Java\jdk1.6.0_43\bin>

Step 3->keytool -list -v -keystore C:\Users\leon\.android\debug.keystore -alias androiddebugkey -storepass android -keypass android

u got SHA1 value click this link u convert ur SHA1 value to HASH KEY

im 100% sure this link will help u

How could I convert data from string to long in c#

You can also use long.TryParse and long.Parse.

long l1;
l1 = long.Parse("1100.25");
//or
long.TryParse("1100.25", out l1);

byte array to pdf

Usually this happens if something is wrong with the byte array.

File.WriteAllBytes("filename.PDF", Byte[]);

This creates a new file, writes the specified byte array to the file, and then closes the file. If the target file already exists, it is overwritten.

Asynchronous implementation of this is also available.

public static System.Threading.Tasks.Task WriteAllBytesAsync 
(string path, byte[] bytes, System.Threading.CancellationToken cancellationToken = null);

urllib and "SSL: CERTIFICATE_VERIFY_FAILED" Error

On Windows, Python does not look at the system certificate, it uses its own located at ?\lib\site-packages\certifi\cacert.pem.

The solution to your problem:

  1. download the domain validation certificate as *.crt or *pem file
  2. open the file in editor and copy it's content to clipboard
  3. find your cacert.pem location: from requests.utils import DEFAULT_CA_BUNDLE_PATH; print(DEFAULT_CA_BUNDLE_PATH)
  4. edit the cacert.pem file and paste your domain validation certificate at the end of the file.
  5. Save the file and enjoy requests!

Write string to text file and ensure it always overwrites the existing content.

System.IO.File.WriteAllText (@"D:\path.txt", contents);
  • If the file exists, this overwrites it.
  • If the file does not exist, this creates it.
  • Please make sure you have appropriate privileges to write at the location, otherwise you will get an exception.

Rethrowing exceptions in Java without losing the stack trace

public int read(byte[] a) throws IOException {
    try {
        return in.read(a);
    } catch (final Throwable t) {
        /* can do something here, like  in=null;  */
        throw t;
    }
}

This is a concrete example where the method throws an IOException. The final means t can only hold an exception thrown from the try block. Additional reading material can be found here and here.

How to show imageView full screen on imageView click?

Actually there are three ways to enable full screnn, visit : https://developer.android.com/training/system-ui/immersive

but if you wanna get full screen when the activity is opened, just put this code in your_activity.java

@Override
public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);
    if (hasFocus) {
        hideSystemUI();
    }
}

private void hideSystemUI() {
    // Enables regular immersive mode.
    // For "lean back" mode, remove SYSTEM_UI_FLAG_IMMERSIVE.
    // Or for "sticky immersive," replace it with SYSTEM_UI_FLAG_IMMERSIVE_STICKY
    View decorView = getWindow().getDecorView();
    decorView.setSystemUiVisibility(
            View.SYSTEM_UI_FLAG_IMMERSIVE
            // Set the content to appear under the system bars so that the
            // content doesn't resize when the system bars hide and show.
            | View.SYSTEM_UI_FLAG_LAYOUT_STABLE
            | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
            | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
            // Hide the nav bar and status bar
            | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
            | View.SYSTEM_UI_FLAG_FULLSCREEN);
}

// Shows the system bars by removing all the flags
// except for the ones that make the content appear under the system bars.
private void showSystemUI() {
    View decorView = getWindow().getDecorView();
    decorView.setSystemUiVisibility(
            View.SYSTEM_UI_FLAG_LAYOUT_STABLE
            | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
            | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
}

How do I remove whitespace from the end of a string in Python?

You can use strip() or split() to control the spaces values as in the following:

words = "   first  second   "

# Remove end spaces
def remove_end_spaces(string):
    return "".join(string.rstrip())


# Remove the first and end spaces
def remove_first_end_spaces(string):
    return "".join(string.rstrip().lstrip())


# Remove all spaces
def remove_all_spaces(string):
    return "".join(string.split())


# Show results
print(words)
print(remove_end_spaces(words))
print(remove_first_end_spaces(words))
print(remove_all_spaces(words))

TABLOCK vs TABLOCKX

Big difference, TABLOCK will try to grab "shared" locks, and TABLOCKX exclusive locks.

If you are in a transaction and you grab an exclusive lock on a table, EG:

SELECT 1 FROM TABLE WITH (TABLOCKX)

No other processes will be able to grab any locks on the table, meaning all queries attempting to talk to the table will be blocked until the transaction commits.

TABLOCK only grabs a shared lock, shared locks are released after a statement is executed if your transaction isolation is READ COMMITTED (default). If your isolation level is higher, for example: SERIALIZABLE, shared locks are held until the end of a transaction.


Shared locks are, hmmm, shared. Meaning 2 transactions can both read data from the table at the same time if they both hold a S or IS lock on the table (via TABLOCK). However, if transaction A holds a shared lock on a table, transaction B will not be able to grab an exclusive lock until all shared locks are released. Read about which locks are compatible with which at msdn.


Both hints cause the db to bypass taking more granular locks (like row or page level locks). In principle, more granular locks allow you better concurrency. So for example, one transaction could be updating row 100 in your table and another row 1000, at the same time from two transactions (it gets tricky with page locks, but lets skip that).

In general granular locks is what you want, but sometimes you may want to reduce db concurrency to increase performance of a particular operation and eliminate the chance of deadlocks.

In general you would not use TABLOCK or TABLOCKX unless you absolutely needed it for some edge case.

$(window).height() vs $(document).height

This fixed me

var width = window.innerWidth;
var height = window.innerHeight;

In SSRS, why do I get the error "item with same key has already been added" , when I'm making a new report?

It appears that SSRS has an issue(at leastin version 2008) - I'm studying this website that explains it

Where it says if you have two columns(from 2 diff. tables) with the same name, then it'll cause that problem.

From source:

SELECT a.Field1, a.Field2, a.Field3, b.Field1, b.field99 FROM TableA a JOIN TableB b on a.Field1 = b.Field1

SQL handled it just fine, since I had prefixed each with an alias (table) name. But SSRS uses only the column name as the key, not table + column, so it was choking.

The fix was easy, either rename the second column, i.e. b.Field1 AS Field01 or just omit the field all together, which is what I did.

java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader

In my case After running the ndk-build in the jni folder the shared library was created under the libs folder but the path specified in build.gradle

sourceSets.main {
        jni.srcDirs = []
        jniLibs.srcDir 'src/main/jniLibs'
    }

so I need to move the created shared library to jnilibs folder and it worked!

How to get a parent element to appear above child

style:

.parent{
  overflow:hidden;
  width:100px;
}

.child{
  width:200px;
}

body:

<div class="parent">
   <div class="child"></div>
</div>

Declaring a python function with an array parameters and passing an array argument to the function call?

What you have is on the right track.

def dosomething( thelist ):
    for element in thelist:
        print element

dosomething( ['1','2','3'] )
alist = ['red','green','blue']
dosomething( alist )  

Produces the output:

1
2
3
red
green
blue

A couple of things to note given your comment above: unlike in C-family languages, you often don't need to bother with tracking the index while iterating over a list, unless the index itself is important. If you really do need the index, though, you can use enumerate(list) to get index,element pairs, rather than doing the x in range(len(thelist)) dance.

Is it safe to clean docker/overlay2/

I found this worked best for me:

docker image prune --all

By default Docker will not remove named images, even if they are unused. This command will remove unused images.

Note each layer in an image is a folder inside the /usr/lib/docker/overlay2/ folder.