Programs & Examples On #Resultevent

How do I correct "Commit Failed. File xxx is out of date. xxx path not found."

I have been unable to find a satisfactory solution to this problem; however, I have found an unsatisfactory solution.

I have deleted all the files within trunk and committed these changes. I then exported my branch code into the trunk, added all the files, and made a large commit. This had the affect of my trunk mimicking my branch 1:1 (which is what I wanted anyway).

Unfortunately, this creates a large divide as the history of all the files is now "lost". But due to time constraints there didn't appear to be any other option.

I will still be interested in any answers that others may have as I would like to know what the root cause was and how to avoid it in the future.

jQuery changing style of HTML element

Use this:

$('#navigation ul li').css('display', 'inline-block');

Also, as others have stated, if you want to make multiple css changes at once, that's when you would add the curly braces (for object notation), and it would look something like this (if you wanted to change, say, 'background-color' and 'position' in addition to 'display'):

$('#navigation ul li').css({'display': 'inline-block', 'background-color': '#fff', 'position': 'relative'}); //The specific CSS changes after the first one, are, of course, just examples.

Chrome dev tools fails to show response even the content returned has header Content-Type:text/html; charset=UTF-8

As described by Gideon, this is a known issue.
For use window.onunload = function() { debugger; } instead.
But you can add a breakpoint in Source tab, then can solve your problem. like this: enter image description here

the best way to make codeigniter website multi-language. calling from lang arrays depends on lang session?

Have you seen CodeIgniter's Language library?

The Language Class provides functions to retrieve language files and lines of text for purposes of internationalization.

In your CodeIgniter system folder you'll find one called language containing sets of language files. You can create your own language files as needed in order to display error and other messages in other languages.

Language files are typically stored in your system/language directory. Alternately you can create a folder called language inside your application folder and store them there. CodeIgniter will look first in your application/language directory. If the directory does not exist or the specified language is not located there CI will instead look in your global system/language folder.

In your case...

  • you need to create a polish_lang.php and english_lang.php inside application/language/polish
  • then create your keys inside that file (e.g. $lang['hello'] = "Witaj";
  • then load it in your controller like $this->lang->load('polish_lang', 'polish');
  • then fetch the line like $this->lang->line('hello'); Just store the return value of this function in a variable so you can use it in your view.

Repeat the steps for the english language and all other languages you need.

How does "make" app know default target to build if no target is specified?

GNU Make also allows you to specify the default make target using a special variable called .DEFAULT_GOAL. You can even unset this variable in the middle of the Makefile, causing the next target in the file to become the default target.

Ref: The Gnu Make manual - Special Variables

How to add a ScrollBar to a Stackpanel

If you mean, you want to scroll through multiple items in your stackpanel, try putting a grid around it. By definition, a stackpanel has infinite length.

So try something like this:

   <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
        <StackPanel Width="311">
              <TextBlock Text="{Binding A}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}" FontStretch="Condensed" FontSize="28" />
              <TextBlock Text="{Binding B}" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>

You could even make this work with a ScrollViewer

What does "pending" mean for request in Chrome Developer Window?

In my case, I found (after much hair-pulling) that the "pending" status was caused by the AdBlock extension. The image that I couldn't get to load had the word "ad" in the URL, so AdBlock kept it from loading.

Disabling AdBlock fixes this issue.

Renaming the file so that it doesn't contain "ad" in the URL also fixes it, and is obviously a better solution. Unless it's an advertisement, in which case you should leave it like that. :)

Android Recyclerview vs ListView with Viewholder

Okay so little bit of digging and I found these gems from Bill Philips article on RecycleView

RecyclerView can do more than ListView, but the RecyclerView class itself has fewer responsibilities than ListView. Out of the box, RecyclerView does not:

  • Position items on the screen
  • Animate views
  • Handle any touch events apart from scrolling

All of this stuff was baked in to ListView, but RecyclerView uses collaborator classes to do these jobs instead.

The ViewHolders you create are beefier, too. They subclass RecyclerView.ViewHolder, which has a bunch of methods RecyclerView uses. ViewHolders know which position they are currently bound to, as well as which item ids (if you have those). In the process, ViewHolder has been knighted. It used to be ListView’s job to hold on to the whole item view, and ViewHolder only held on to little pieces of it.

Now, ViewHolder holds on to all of it in the ViewHolder.itemView field, which is assigned in ViewHolder’s constructor for you.

Concatenating null strings in Java

This is behavior specified in the Java API's String.valueOf(Object) method. When you do concatenation, valueOf is used to get the String representation. There is a special case if the Object is null, in which case the string "null" is used.

public static String valueOf(Object obj)

Returns the string representation of the Object argument.

Parameters: obj - an Object.


if the argument is null, then a string equal to "null"; otherwise, the value of obj.toString() is returned.

How to parse XML and count instances of a particular node attribute?

A new lib, I fell in love with it after I used it. I recommend it to you.

from simplified_scrapy import SimplifiedDoc
xml = '''
      <type foobar="1"/>
      <type foobar="2"/>

doc = SimplifiedDoc(xml)
types = doc.selects('bar>type')
print (len(types)) # 2
print (types.foobar) # ['1', '2']
print (doc.selects('bar>type>foobar()')) # ['1', '2']

Here are more examples. This lib is easy to use.

Set opacity of background image without affecting child elements

If you have to set the opacity only to the bullet, why don't you set the alpha channel directly into the image? By the way I don't think there is a way to set the opacity to a background image via css without changing the opacity of the whole element (and its children too).

How do you connect localhost in the Android emulator?

Use to access your actual machine.

As you've learned, when you use the emulator, localhost ( refers to the device's own loopback service, not the one on your machine as you may expect.

You can use to access your actual machine, it is an alias set up to help in development.

Webdriver Unable to connect to host on port 7055 after 45000 ms

Update selenium jars, download selenium 2.31.0

This issue has been resolved by the selenium guys

This was a compatibility issue.


Finish all previous activities


Intent intent = new Intent(getApplicationContext(), Home.class);

This will clear all the activities on top of home.

Assuming you are finishing the login screen when the user logs in and home is created and afterwards all the screens from 1 to 5 on top of that one. The code i posted will return you to home screen finishing all the other activites. You can add an extra in the intent and read that in the home screen activity and finish it also (maybe launch login screen again from there or something).

I am not sure but you can also try going to login with this flag. I don't know how the activities will be ordered in that case. So don't know if it will clear the ones below the screen you are on including the one you are currently on but its definitely the way to go.

Hope this helps.

Echo newline in Bash prints literal \n

It works for me in CentOS:

echo -e ""hello\nworld""

Using If else in SQL Select statement

Here are two ways "IF" Or "CASE".




Using openssl to get the certificate from a server

It turns out there is more complexity here: I needed to provide many more details to get this rolling. I think its something to do with the fact that its a connection that needs client authentication, and the hankshake needed more info to continue to the stage where the certificates were dumped.

Here is my working command:

openssl s_client -connect host:port -key our_private_key.pem -showcerts \
                 -cert our_server-signed_cert.pem

Hopefully this is a nudge in the right direction for anyone who could do with some more info.

Npm install failed with "cannot run in wd"

The documentation says (also here):

If npm was invoked with root privileges, then it will change the uid to the user account or uid specified by the user config, which defaults to nobody. Set the unsafe-perm flag to run scripts with root privileges.

Your options are:

  1. Run npm install with the --unsafe-perm flag:

    [sudo] npm install --unsafe-perm
  2. Add the unsafe-perm flag to your package.json:

    "config": {
  3. Don't use the preinstall script to install global modules, install them separately and then run the regular npm install without root privileges:

    sudo npm install -g coffee-script node-gyp
    npm install


SQL string value spanning multiple lines in query

What's the column "BIO" datatype? What database server (sql/oracle/mysql)? You should be able to span over multiple lines all you want as long as you adhere to the character limit in the column's datatype (ie: varchar(200) ). Try using single quotes, that might make a difference. This works for me:

update table set mycolumn = 'hello world,
my name is carlos.
where id = 1;

Also, you might want to put in checks for single quotes if you are concatinating the sql string together in C#. If the variable contains single quotes that could escape the code out of the sql statement, therefore, not doing all the lines you were expecting to see.

BTW, you can delimit your SQL statements with a semi colon like you do in C#, just as FYI.

How to replace negative numbers in Pandas Data Frame by zero

Perhaps you could use pandas.where(args) like so:

data_frame = data_frame.where(data_frame < 0, 0)

How to use systemctl in Ubuntu 14.04

Ubuntu 14 and lower does not have "systemctl" Source:

Configure Docker to start on boot:

Most current Linux distributions (RHEL, CentOS, Fedora, Ubuntu 16.04 and higher) use systemd to manage which services start when the system boots. Ubuntu 14.10 and below use upstart.

1) systemd (Ubuntu 16 and above):

$ sudo systemctl enable docker

To disable this behavior, use disable instead.

$ sudo systemctl disable docker

2) upstart (Ubuntu 14 and below):

Docker is automatically configured to start on boot using upstart. To disable this behavior, use the following command:

$ echo manual | sudo tee /etc/init/docker.override

$ sudo chkconfig docker on


What is Scala's yield?

yield is more flexible than map(), see example below

val aList = List( 1,2,3,4,5 )

val res3 = for ( al <- aList if al > 3 ) yield al + 1 
val res4 = _+ 1 > 3 ) 

println( res3 )
println( res4 )

yield will print result like: List(5, 6), which is good

while map() will return result like: List(false, false, true, true, true), which probably is not what you intend.

Create an empty object in JavaScript with {} or new Object()?

var objectA = {}

is a lot quicker and, in my experience, more commonly used, so it's probably best to adopt the 'standard' and save some typing.

Android 'Unable to add window -- token null is not for an application' exception

In my case I was trying to create my dialog like this:

new Dialog(getApplicationContext());

So I had to change for:

new Dialog(this);

And it works fine for me ;)

RegEx to parse or validate Base64 data

Neither a ":" nor a "." will show up in valid Base64, so I think you can unambiguously throw away the line. In Perl, say, something like

my $sanitized_str = join q{}, grep {!/[^A-Za-z0-9+\/=]/} split /\n/, $str;

say decode_base64($sanitized_str);

might be what you want. It produces

This is simple ASCII Base64 for StackOverflow exmaple.

I'm getting Key error in python

For example, if this is a number :


It's work perfectly, but if you use for example :

ouloulou[input("select 1 2 or 3"]()

it's doesn't work, because your input return string '1'. So you need to use int()

ouloulou[int(input("select 1 2 or 3"))]()

.append(), prepend(), .after() and .before()

append() & prepend() are for inserting content inside an element (making the content its child) while after() & before() insert content outside an element (making the content its sibling).

What is the official name for a credit card's 3 digit code?

It is called the Card Security Code (CSC) according to Wikipedia, but has also been known as other things, such as the Card Verification Value (CVV) or Card Verfication Code (CVC).

The second code, and the most cited, is CVV2 or CVC2. This CSC (also known as a CCID or Credit Card ID) is often asked for by merchants for them to secure "card not present" transactions occurring over the Internet, by mail, fax or over the phone. In many countries in Western Europe, due to increased attempts at card fraud, it is now mandatory to provide this code when the cardholder is not present in person.

Because this seems to be known by multiple names, and its name doesn't seem to be printed on the card itself, you'll probably (unfortunately) still need to tell your users how to find the code - ie by describing it as the "3 digit code on back of card".

2018 update

The situation has not improved, and is now worse - there are even more different names now. However, you can if you like use different terms depending on the card type:

  • "CVC2" or "Card Validation Code" – MasterCard
  • "CVV2" or "Card Verification Value 2" – Visa
  • "CSC" or "Card Security Code" – American Express

Note that some American Express and Discover cards use a 4-digit code on the front of the card. See the above linked Wikipedia article for more.

Convert date to YYYYMM format

A more efficient method, that uses integer math rather than strings/varchars, that will result in an int type rather than a string type is:


Adds two zeros to the right side of the year and then adds the month to the added two zeros.

Prevent textbox autofill with previously entered values

This works for me

   <script type="text/javascript">
        var c = document.getElementById("<%=TextBox1.ClientID %>"); =
        function (event, ui) 
        { this.value = ""; return false; }

How do I extract the contents of an rpm?

In NixOS, there is rpmextract. It is a wrapper around rpm2cpio, exactly as @Alan Evangelista wanted.

using batch echo with special characters

The answer from Joey was not working for me. After executing

  echo ^<?xml version="1.0" encoding="utf-8" ?^> > myfile.xml

I got this error bash: syntax error near unexpected token `>'

This solution worked for me:

 echo "<?xml version=\"1.0\" encoding=\"utf-8\">" > myfile.txt

See also

Transferring files over SSH

No, you still need to scp [from] [to] whichever way you're copying

The difference is, you need to scp -p server:serverpath localpath

How to replace blank (null ) values with 0 for all records?

Using find and replace will work if you type "null" in the find and put a zero in the will be warned that this cannot be undone.

How to find specified name and its value in JSON-string from Java?

Use a JSON library to parse the string and retrieve the value.

The following very basic example uses the built-in JSON parser from Android.

String jsonString = "{ \"name\" : \"John\", \"age\" : \"20\", \"address\" : \"some address\" }";
JSONObject jsonObject = new JSONObject(jsonString);
int age = jsonObject.getInt("age");

More advanced JSON libraries, such as jackson, google-gson, json-io or genson, allow you to convert JSON objects to Java objects directly.

MVC 4 client side validation not working

For me this was a lot of searching. Eventually I decided to use NuGet instead of downloading the files myself. I deleted all involved scripts and scriptbundles and got the following packages (latest versions as of now)

  • jQuery (3.1.1)
  • jQuery Validation (1.15.1)
  • Microsoft jQuery Ubobtrusive Ajax (3.2.3)
  • Microsoft jQuery Unobtrusive Validation (3.2.3)

Then I added these bundles to the BundleConfig file:

bundles.Add(new ScriptBundle("~/bundles/jquery").Include(

bundles.Add(new ScriptBundle("~/bundles/jqueryval").Include(

I added this reference to _Layout.cshtml:


And I added this reference to whichever view I needed validation:


Now everything worked.

Don't forget these things (many people forget them):

  • Form tags (@using (Html.BeginForm()))
  • Validation Summary (@Html.ValidationSummary())
  • Validation Message on your input (Example: @Html.ValidationMessageFor(model => model.StartDate))
  • Configuration ()
  • The order of the files added to the bundle (as stated above)

Vertical align middle with Bootstrap responsive grid

.row {
    letter-spacing: -.31em;
    word-spacing: -.43em;
.col-md-4 {
    float: none;
    display: inline-block;
    vertical-align: middle;

Note: .col-md-4 could be any grid column, its just an example here.

How to change theme for AlertDialog

Better way to do this use custom dialog and customize according your needs here is custom dialog example.....

enter image description here

public class CustomDialogUI {
Dialog dialog;
Vibrator vib;
RelativeLayout rl;

public void dialog(final Context context, String title, String message,
        final Runnable task) {
    dialog = new Dialog(context);
    TextView m = (TextView) dialog.findViewById(;
    TextView t = (TextView) dialog.findViewById(;
    final Button n = (Button) dialog.findViewById(;
    final Button p = (Button) dialog.findViewById(;
    rl = (RelativeLayout) dialog.findViewById(;
    // color(context,rl);
    vib = (Vibrator) context.getSystemService(context.VIBRATOR_SERVICE);
    n.setOnClickListener(new OnClickListener() {
        public void onClick(View arg0) {
    p.setOnClickListener(new OnClickListener() {
        public void onClick(View arg0) {
 //customize text style bold italic....
public SpannableString bold(String s) {
    SpannableString spanString = new SpannableString(s);
    spanString.setSpan(new StyleSpan(Typeface.BOLD), 0,
            spanString.length(), 0);
    spanString.setSpan(new UnderlineSpan(), 0, spanString.length(), 0);
    // spanString.setSpan(new StyleSpan(Typeface.ITALIC), 0,
    // spanString.length(), 0);
    return spanString;


Here is xml layout

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android=""

    android:background="#569CE3" >

        android:layout_marginTop="10dip" >

            android:text="Are you Sure?"
            android:textSize="13dip" />

        android:layout_marginTop="5dip" >

        android:layout_marginTop="3dip" />

        android:layout_toLeftOf="@+id/process" >

            android:text="Medium Text"



        android:text="Okay" />



Removing elements by class name?

Yes, you have to remove from the parent:


Why does using an Underscore character in a LIKE filter give me all the results?

In case people are searching how to do it in BigQuery:

  • An underscore "_" matches a single character or byte.

  • You can escape "\", "_", or "%" using two backslashes. For example, "\%". If you are using raw strings, only a single backslash is required. For example, r"\%".

WHERE mycolumn LIKE '%\\_%'


How to select a CRAN mirror in R

Here is what I do, which is basically straight from the example(Startup) page:

## Default repo
local({r <- getOption("repos")
       r["CRAN"] <- "" 

which is in ~/.Rprofile.

Edit: As it is now 2018, we can add that for the last few years the URL "" has been preferable as it reflects a) https access and b) an "always-near-you" CDN.

Should I use JSLint or JSHint JavaScript validation?

Well, Instead of doing manual lint settings we can include all the lint settings at the top of our JS file itself e.g.

Declare all the global var in that file like:

/*global require,dojo,dojoConfig,alert */

Declare all the lint settings like:

/*jslint browser:true,sloppy:true,nomen:true,unparam:true,plusplus:true,indent:4 */

Hope this will help you :)

Case Function Equivalent in Excel

If you don't have a SWITCH statement in your Excel version (pre-Excel-2016), here's a VBA implementation for it:

Public Function SWITCH(ParamArray args() As Variant) As Variant
    Dim i As Integer
    Dim val As Variant
    Dim tmp As Variant

    If ((UBound(args) - LBound(args)) = 0) Or (((UBound(args) - LBound(args)) Mod 2 = 0)) Then
        Error 450       'Invalid arguments
        val = args(LBound(args))
        i = LBound(args) + 1
        tmp = args(UBound(args))

        While (i < UBound(args))
            If val = args(i) Then
                tmp = args(i + 1)
            End If
            i = i + 2
    End If

    SWITCH = tmp
End Function

It works exactly like expected, a drop-in replacement for example for Google Spreadsheet's SWITCH function.


=SWITCH(selector; [keyN; valueN;] ...  defaultvalue)


  • selector is any expression that is compared to keys
  • key1, key2, ... are expressions that are compared to the selector
  • value1, value2, ... are values that are selected if the selector equals to the corresponding key (only)
  • defaultvalue is used if no key matches the selector


=SWITCH("a";"?")                       returns "?"
=SWITCH("a";"a";"1";"?")               returns "1"
=SWITCH("x";"a";"1";"?")               returns "?"
=SWITCH("b";"a";"1";"b";TRUE;"?")      returns TRUE
=SWITCH(7;7;1;7;2;0)                   returns 2
=SWITCH("a";"a";"1")                   returns #VALUE!

To use it, open your Excel, go to Develpment tools tab, click Visual Basic, rightclick on ThisWorkbook, choose Insert, then Module, finally copy the code into the editor. You have to save as a macro-friendly Excel workbook (xlsm).

how do I change text in a label with swift?

Swift uses the same cocoa-touch API. You can call all the same methods, but they will use Swift's syntax. In this example you can do something like this:

self.simpleLabel.text = "message"

Note the setText method isn't available. Setting the label's text with = will automatically call the setter in swift.

filter: progid:DXImageTransform.Microsoft.gradient is not working in ie7

In testing IE7/8/9 I was getting an ActiveX warning trying to use this code snippet:


After removing this the warning went away. I know this isn't an answer, but I thought it was worthwhile to note.

How to auto-size an iFrame?

On any other element, I would use the scrollHeight of the DOM object and set the height accordingly. I don't know if this would work on an iframe (because they're a bit kooky about everything) but it's certainly worth a try.

Edit: Having had a look around, the popular consensus is setting the height from within the iframe using the offsetHeight:

function setHeight() {
    parent.document.getElementById('the-iframe-id').style.height = document['body'].offsetHeight + 'px';

And attach that to run with the iframe-body's onLoad event.

How do I check if string contains substring?

You could use search or match for this. 'Yes' )

will return the position of the match, or -1 if it isn't found.

Append Char To String in C?

If Linux is your concern, the easiest way to append two strings:

char * append(char * string1, char * string2)
    char * result = NULL;
    asprintf(&result, "%s%s", string1, string2);
    return result;

This won't work with MS Visual C.

Note: you have to free() the memory returned by asprintf()

How do I catch a PHP fatal (`E_ERROR`) error?

If you are using PHP >= 5.1.0 Just do something like this with the ErrorException class:

    // Define an error handler
    function exception_error_handler($errno, $errstr, $errfile, $errline ) {
        throw new ErrorException($errstr, $errno, 0, $errfile, $errline);

    // Set your error handler

    /* Trigger exception */
        // Try to do something like finding the end of the internet
    catch(ErrorException $e)
        // Anything you want to do with $e

JPA With Hibernate Error: [PersistenceUnit: JPA] Unable to build EntityManagerFactory

You don't need both hibernate.cfg.xml and persistence.xml in this case. Have you tried removing hibernate.cfg.xml and mapping everything in persistence.xml only?

But as the other answer also pointed out, this is not okay like this:

@JoinColumn(name = "categoria") 
private String id;

Didn't you want to use @Column instead?

What is the use of "assert"?

Here is a simple example, save this in file (let's say

def chkassert(num):
    assert type(num) == int


and the result when $python

Traceback (most recent call last):
  File "", line 5, in <module>
  File "", line 2, in chkassert
    assert type(num) == int

How to print a stack trace in Node.js?

Any Error object has a stack member that traps the point at which it was constructed.

var stack = new Error().stack
console.log( stack )

or more simply:

console.trace("Here I am!")

How to get the Android device's primary e-mail address

I would use Android's AccountPicker, introduced in ICS.

Intent googlePicker = AccountPicker.newChooseAccountIntent(null, null, new String[]{GoogleAuthUtil.GOOGLE_ACCOUNT_TYPE}, true, null, null, null, null);
startActivityForResult(googlePicker, REQUEST_CODE);

And then wait for the result:

protected void onActivityResult(final int requestCode, final int resultCode,
                                final Intent data) {
    if (requestCode == REQUEST_CODE && resultCode == RESULT_OK) {
        String accountName = data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);

How to convert Strings to and from UTF8 byte arrays in Java

//query is your json   

 DefaultHttpClient httpClient = new DefaultHttpClient();
 HttpPost postRequest = new HttpPost("");

 StringEntity input = new StringEntity(query, "UTF-8");
 HttpResponse response=response = httpClient.execute(postRequest);

Mosaic Grid gallery with dynamic sized images

I suggest Freewall. It is a cross-browser and responsive jQuery plugin to help you create many types of grid layouts: flexible layouts, images layouts, nested grid layouts, metro style layouts, pinterest like layouts ... with nice CSS3 animation effects and call back events. Freewall is all-in-one solution for creating dynamic grid layouts for desktop, mobile, and tablet.

Home page and document: also found here.

Where's my invalid character (ORA-00911)

One of the reason may be if any one of table column have an underscore(_) in its name . That is considered as invalid characters by the JDBC . Rename the column by a ALTER Command and change in your code SQL , that will fix .

How to set text color in submit button?

you try this:

<input type="submit" style="font-face: 'Comic Sans MS'; font-size: larger; color: teal; background-color: #FFFFC0; border: 3pt ridge lightgrey" value=" Send Me! ">

ASP.NET Custom Validator Client side & Server Side validation not firing

Your CustomValidator will only fire when the TextBox isn't empty.

If you need to ensure that it's not empty then you'll need a RequiredFieldValidator too.

Note: If the input control is empty, no validation functions are called and validation succeeds. Use a RequiredFieldValidator control to require the user to enter data in the input control.


If your CustomValidator specifies the ControlToValidate attribute (and your original example does) then your validation functions will only be called when the control isn't empty.

If you don't specify ControlToValidate then your validation functions will be called every time.

This opens up a second possible solution to the problem. Rather than using a separate RequiredFieldValidator, you could omit the ControlToValidate attribute from the CustomValidator and setup your validation functions to do something like this:

Client Side code (Javascript):

function TextBoxDCountyClient(sender, args) {
    var v = document.getElementById('<%=TextBoxDTownCity.ClientID%>').value;
    if (v == '') {
        args.IsValid = false;  // field is empty
    else {
        // do your other validation tests here...

Server side code (C#):

protected void TextBoxDTownCity_Validate(
    object source, ServerValidateEventArgs args)
    string v = TextBoxDTownCity.Text;
    if (v == string.Empty)
        args.IsValid = false;  // field is empty
        // do your other validation tests here...

How do you stretch an image to fill a <div> while keeping the image's aspect-ratio?

try this


<div class="container"></div>


background-image: url("...");
background-size: 100%;
background-position: center;

How do I get monitor resolution in Python?

Old question but this is missing. I'm new to python so please tell me if this is a "bad" solution. This solution is supported for Windows and MacOS only and it works just for the main screen - but the os is not mentioned in the question.

Measure the size by taking a screenshot. As the screensize should not change this has to be done only once. There are more elegant solutions if you have a gui toolkit like GTK, wx, ... installed.

see Pillow

pip install Pillow

from PIL import ImageGrab

img = ImageGrab.grab()
print (img.size)

How can I generate a unique ID in Python?

unique and random are mutually exclusive. perhaps you want this?

import random
def uniqueid():
    seed = random.getrandbits(32)
    while True:
       yield seed
       seed += 1


unique_sequence = uniqueid()
id1 = next(unique_sequence)
id2 = next(unique_sequence)
id3 = next(unique_sequence)
ids = list(itertools.islice(unique_sequence, 1000))

no two returned id is the same (Unique) and this is based on a randomized seed value

What is %2C in a URL?

It's the ASCII keycode in hexadecimal for a comma (,).

i.e. , = %2C

like in my link suppose i want to order by two fields means in my link it will come like

order_by=id%2Cname which is equal to order_by=id,name .

Node Multer unexpected field

The <NAME> you use in multer's upload.single(<NAME>) function must be the same as the one you use in <input type="file" name="<NAME>" ...>.

So you need to change

var type = upload.single('file')


var type = upload.single('recfile')

in you app.js

Hope this helps.

Insert text into textarea with jQuery

I used that and it work fine :)

$("#textarea").html("Put here your content");


How do I create an abstract base class in JavaScript?

I think All Those answers specially first two (by some and jordão) answer the question clearly with conventional prototype base JS concept.
Now as you want the animal class constructor to behave according to the passed parameter to the construction, I think this is very much similar to basic behavior of Creational Patterns for example Factory Pattern.

Here i made a little approach to make it work that way.

var Animal = function(type) {
        return new Dog();
    else if(type=="cat")
        return new Cat();

    console.log("I am a "+this.type);

Animal.prototype.say = function(){
    console.log("Not implemented");

var Cat =function () {;

Cat.prototype.constructor = Cat;


var Dog =function () {;

Dog.prototype.constructor = Dog;


var animal=new Animal();

var dog = new Animal('dog');
var cat=new Animal('cat');

animal.whoAreYou(); //I am a undefined
animal.say(); //Not implemented

dog.whoAreYou(); //I am a dog
dog.say(); //bark

cat.whoAreYou(); //I am a cat
cat.say(); //meow

How does System.out.print() work?

You can convert anything to a String as long as you choose what to print. The requirement was quite simple since Objet.toString() can return a default dumb string: package.classname + @ + object number.

If your print method should return an XML or JSON serialization, the basic result of toString() wouldn't be acceptable. Even though the method succeed.

Here is a simple example to show that Java can be dumb

public class MockTest{

String field1;

String field2;

public MockTest(String field1,String field2){


System.out.println(new MockTest("a","b");

will print something package.Mocktest@3254487 ! Even though you only have two String members and this could be implemented to print


(or pretty much how it appears in the debbuger)

When do I use path params vs. query params in a RESTful API?

Best practice for RESTful API design is that path params are used to identify a specific resource or resources, while query parameters are used to sort/filter those resources.

Here's an example. Suppose you are implementing RESTful API endpoints for an entity called Car. You would structure your endpoints like this:

GET /cars
GET /cars/:id
POST /cars
PUT /cars/:id
DELETE /cars/:id

This way you are only using path parameters when you are specifying which resource to fetch, but this does not sort/filter the resources in any way.

Now suppose you wanted to add the capability to filter the cars by color in your GET requests. Because color is not a resource (it is a property of a resource), you could add a query parameter that does this. You would add that query parameter to your GET /cars request like this:

GET /cars?color=blue

This endpoint would be implemented so that only blue cars would be returned.

As far as syntax is concerned, your URL names should be all lowercase. If you have an entity name that is generally two words in English, you would use a hyphen to separate the words, not camel case.

Ex. /two-words

How can I one hot encode in Python?

Here is a solution using DictVectorizer and the Pandas DataFrame.to_dict('records') method.

>>> import pandas as pd
>>> X = pd.DataFrame({'income': [100000,110000,90000,30000,14000,50000],
                      'country':['US', 'CAN', 'US', 'CAN', 'MEX', 'US'],
                      'race':['White', 'Black', 'Latino', 'White', 'White', 'Black']

>>> from sklearn.feature_extraction import DictVectorizer
>>> v = DictVectorizer()
>>> qualitative_features = ['country','race']
>>> X_qual = v.fit_transform(X[qualitative_features].to_dict('records'))
>>> v.vocabulary_
{'country=CAN': 0,
 'country=MEX': 1,
 'country=US': 2,
 'race=Black': 3,
 'race=Latino': 4,
 'race=White': 5}

>>> X_qual.toarray()
array([[ 0.,  0.,  1.,  0.,  0.,  1.],
       [ 1.,  0.,  0.,  1.,  0.,  0.],
       [ 0.,  0.,  1.,  0.,  1.,  0.],
       [ 1.,  0.,  0.,  0.,  0.,  1.],
       [ 0.,  1.,  0.,  0.,  0.,  1.],
       [ 0.,  0.,  1.,  1.,  0.,  0.]])

Regular Expression for password validation

Try this ( also corrected check for upper case and lower case, it had a bug since you grouped them as [a-zA-Z] it only looks for atleast one lower or upper. So separated them out ):


Update: I found that the regex doesn't really work as expected and this is not how it is supposed to be written too!

Try something like this:


(Between 8 and 15 inclusive, contains atleast one digit, atleast one upper case and atleast one lower case and no whitespace.)

And I think this is easier to understand as well.

Update or Insert (multiple rows and columns) from subquery in PostgreSQL

UPDATE table1 SET (col1, col2) = (col2, col3) FROM othertable WHERE othertable.col1 = 123;

Transform DateTime into simple Date in Ruby on Rails

I recently wrote a gem to simplify this process and to neaten up your views, etc etc.

Check it out at:

Sort hash by key, return hash in Ruby

ActiveSupport::OrderedHash is another option if you don't want to use ruby 1.9.2 or roll your own workarounds.

What do *args and **kwargs mean?

Putting *args and/or **kwargs as the last items in your function definition’s argument list allows that function to accept an arbitrary number of arguments and/or keyword arguments.

For example, if you wanted to write a function that returned the sum of all its arguments, no matter how many you supply, you could write it like this:

def my_sum(*args):
    return sum(args)

It’s probably more commonly used in object-oriented programming, when you’re overriding a function, and want to call the original function with whatever arguments the user passes in.

You don’t actually have to call them args and kwargs, that’s just a convention. It’s the * and ** that do the magic.

The official Python documentation has a more in-depth look.

Extract a single (unsigned) integer from a string

$value = '25%';


$value = '25.025$';


$value = 'I am numeric 25';

This will return only the numeric value

VIM Disable Automatic Newline At End Of File

OK, you being on Windows complicates things ;)

As the 'binary' option resets the 'fileformat' option (and writing with 'binary' set always writes with unix line endings), let's take out the big hammer and do it externally!

How about defining an autocommand (:help autocommand) for the BufWritePost event? This autocommand is executed after every time you write a whole buffer. In this autocommand call a small external tool (php, perl or whatever script) that strips off the last newline of the just written file.

So this would look something like this and would go into your .vimrc file:

autocmd!   "Remove all autocmds (for current group), see below"
autocmd BufWritePost *.php !your-script <afile>

Be sure to read the whole vim documentation about autocommands if this is your first time dealing with autocommands. There are some caveats, e.g. it's recommended to remove all autocmds in your .vimrc in case your .vimrc might get sourced multiple times.

Draw on HTML5 Canvas using a mouse

A super short version, here, without position:absolute in vanilla JavaScript. The main idea is to move the canvas' context to the right coordinates and draw a line. Uncomment click handler and comment mousedown & mousemove handlers below to get a feel for how it is working.

<!DOCTYPE html>

<p style="margin: 50px">Just some padding in y direction</p>

<canvas id="myCanvas" width="300" height="300" style="background: #000; margin-left: 100px;">Your browser does not support the HTML5 canvas tag.</canvas>

    const c = document.getElementById("myCanvas");
    // c.addEventListener("click", penTool); // fires after mouse left btn is released
    c.addEventListener("mousedown", setLastCoords); // fires before mouse left btn is released
    c.addEventListener("mousemove", freeForm);

    const ctx = c.getContext("2d");

    function setLastCoords(e) {
        const {x, y} = c.getBoundingClientRect();
        lastX = e.clientX - x;
        lastY = e.clientY - y;

    function freeForm(e) {
        if (e.buttons !== 1) return; // left button is not pushed yet

    function penTool(e) {
        const {x, y} = c.getBoundingClientRect();
        const newX = e.clientX - x;
        const newY = e.clientY - y;

        ctx.lineWidth = 5;
        ctx.moveTo(lastX, lastY);
        ctx.lineTo(newX, newY);
        ctx.strokeStyle = 'white';

        lastX = newX;
        lastY = newY;

    let lastX = 0;
    let lastY = 0;  


How do I syntax check a Bash script without running it?

I actually check all bash scripts in current dir for syntax errors WITHOUT running them using find tool:


find . -name '*.sh' -exec bash -n {} \;

If you want to use it for a single file, just edit the wildcard with the name of the file.

Nullable type as a generic parameter possible?

I just encountered the same problem myself.

... = reader["myYear"] as int?; works and is clean.

It works with any type without an issue. If the result is DBNull, it returns null as the conversion fails.

Attaching click event to a JQuery object not yet added to the DOM

You have to append it. Create the element with:

var $div = $("<div>my div</div>");
return $div;

Then if you append it will work.

Take a look at your example here and a simple version here.

Disable Rails SQL logging in console

Here's a variation I consider somewhat cleaner, that still allows potential other logging from AR. In config/environments/development.rb :

config.after_initialize do
  ActiveRecord::Base.logger = Rails.logger.clone
  ActiveRecord::Base.logger.level = Logger::INFO

Can I safely delete contents of Xcode Derived data folder?

Yes, you can delete all files from DerivedData sub-folder (Not DerivedData Folder) directly.

That will not affect your project work. Contents of DerivedData folder is generated during the build time and you can delete them if you want. It's not an issue.

The contents of DerivedData will be recreated when you build your projects again.

Xcode8+ Update

From the Xcode8 that removed project option from the window tab so you can still use first way:

Xcode -> Preferences -> location -> click on small arrow button as i explain in my first answer.

Xcode7.3 Update For remove particular project's DeriveData you just need to follow the following steps:

Go to Window -> Project:

enter image description here

You can find the list of project and you can either go the DerivedData Folder or you can direct delete individual Project's DerivedData

enter image description here

I am not working on Xcode5 but in 4.6.3 you can find DerivedData folder as found in the below image:

enter image description here

After clicking on Preferences..

enter image description here

You get this window

enter image description here

Determine whether an array contains a value

Wow, there are a lot of great answers to this question.

I didn't see one that takes a reduce approach so I'll add it in:

var searchForValue = 'pig';

var valueIsInArray = ['horse', 'cat', 'dog'].reduce(function(previous, current){
    return previous || searchForValue === current ? true : false;
}, false);

console.log('The value "' + searchForValue + '" is in the array: ' + valueIsInArray);

Here's a fiddle of it in action.

Jersey Exception : SEVERE: A message body reader for Java class

Just check if you are running different instances in eclipse. I quit all my other sessions, clean build fixed the problem

How do I solve this "Cannot read property 'appendChild' of null" error?

For all those facing a similar issue, I came across this same issue when i was trying to run a particular code snippet, shown below.

                var div, container = document.getElementById("container")
                for(var i=0;i<5;i++){
                    div = document.createElement("div");
                    div.onclick = function() { 
                        alert("This is a box #"+i);

        <div id="container"></div>

Looking at the error in the console for the above code.

Since the document.getElementById is returning a null and as null does not have a attribute named appendChild, therefore a error is thrown. To solve the issue see the code below.

            height: 200px;
            width: 700px;
            background-color: red;
            margin: 10px;

            height: 100px;
            width: 100px;
            background-color: purple;
            margin: 20px;
            display: inline-block;
        <div id="container"></div>
                var div, container = document.getElementById("container")
                for(let i=0;i<5;i++){
                    div = document.createElement("div");
                    div.onclick = function() { 
                        alert("This is a box #"+i);

I hope this helps. :)

Split string in Lua?

You could use penlight library. This has a function for splitting string using delimiter which outputs list.

It has implemented many of the function that we may need while programming and missing in Lua.

Here is the sample for using it.

> stringx = require "pl.stringx"
> str = "welcome to the world of lua"
> arr = stringx.split(str, " ")
> arr

Find the smallest positive integer that does not occur in a given sequence

This solution is in Javascript but complete the test with 100% score and less codes

function solution(A) {
    let s = A.sort((a, b) => { return a - b })
    let x = s.find(o => !s.includes(o+1) && o>0)
    return ((x<0) || !s.includes(1)) ? 1 : x+1

How to do parallel programming in Python?

You can use joblib library to do parallel computation and multiprocessing.

from joblib import Parallel, delayed

You can simply create a function foo which you want to be run in parallel and based on the following piece of code implement parallel processing:

output = Parallel(n_jobs=num_cores)(delayed(foo)(i) for i in input)

Where num_cores can be obtained from multiprocessing library as followed:

import multiprocessing

num_cores = multiprocessing.cpu_count()

If you have a function with more than one input argument, and you just want to iterate over one of the arguments by a list, you can use the the partial function from functools library as follow:

from joblib import Parallel, delayed
import multiprocessing
from functools import partial
def foo(arg1, arg2, arg3, arg4):
    body of the function
    return output
input = [11,32,44,55,23,0,100,...] # arbitrary list
num_cores = multiprocessing.cpu_count()
foo_ = partial(foo, arg2=arg2, arg3=arg3, arg4=arg4)
# arg1 is being fetched from input list
output = Parallel(n_jobs=num_cores)(delayed(foo_)(i) for i in input)

You can find a complete explanation of the python and R multiprocessing with couple of examples here.

Getting URL hash location, and using it in jQuery

Editor's note: the approach below has serious security implications and, depending upon the version of jQuery you are using, may expose your users to XSS attacks. For more detail, see the discussion of the possible attack in the comments on this answer or this explanation on Security Stack Exchange.

You can use the location.hash property to grab the hash of the current page:

var hash = window.location.hash;

Note that this property already contains the # symbol at the beginning.

Actually you don't need the :first pseudo-selector since you are using the ID selector, is assumed that IDs are unique within the DOM.

In case you want to get the hash from an URL string, you can use the String.substring method:

var url = "";
var hash = url.substring(url.indexOf('#')); // '#foo'

Advice: Be aware that the user can change the hash as he wants, injecting anything to your selector, you should check the hash before using it.

An invalid form control with name='' is not focusable

Not only required field as mentioned in other answers. Its also caused by placing a <input> field in a hidden <div> which holds a invalid value.

Consider below example,

<div style="display:none;">
   <input type="number" name="some" min="1" max="50" value="0">

This throws the same error. So make sure the <input> fields inside hidden <div> doesnt hold any invalid value.

How to convert an integer to a character array using C

'sprintf' will work fine, if your first argument is a pointer to a character (a pointer to a character is an array in 'c'), you'll have to make sure you have enough space for all the digits and a terminating '\0'. For example, If an integer uses 32 bits, it has up to 10 decimal digits. So your code should look like:

int i;
char s[11]; 
sprintf(s,"%ld", i);

Total size of the contents of all the files in a directory

Just an alternative:

ls -lAR | grep -v '^d' | awk '{total += $5} END {print "Total:", total}'

grep -v '^d' will exclude the directories.

Python Function to test ping

It looks like you want the return keyword

def check_ping():
    hostname = "taylor"
    response = os.system("ping -c 1 " + hostname)
    # and then check the response...
    if response == 0:
        pingstatus = "Network Active"
        pingstatus = "Network Error"

    return pingstatus

You need to capture/'receive' the return value of the function(pingstatus) in a variable with something like:

pingstatus = check_ping()

NOTE: ping -c is for Linux, for Windows use ping -n

Some info on python functions:

It's probably worth going through a good introductory tutorial to Python, which will cover all the fundamentals. I recommend investigating and

Jquery, checking if a value exists in array or not

If you want to do it using .map() or just want to know how it works you can do it like this:

var added=false;
$.map(arr, function(elementOfArray, indexInArray) {
 if ( == productID) {
   elementOfArray.price = productPrice;
   added = true;
if (!added) {
  arr.push({id: productID, price: productPrice})

The function handles each element separately. The .inArray() proposed in other answers is probably the more efficient way to do it.

How do you run a SQL Server query from PowerShell?

There isn't a built-in "PowerShell" way of running a SQL query. If you have the SQL Server tools installed, you'll get an Invoke-SqlCmd cmdlet.

Because PowerShell is built on .NET, you can use the ADO.NET API to run your queries.

How do I get total physical memory size using PowerShell without WMI?

I'd like to make a note of this for people referencing in the future.

I wanted to avoid WMI because it uses a DCOM protocol, requiring the remote computer to have the necessary permissions, which could only be setup manually on that remote computer.

So, I wanted to avoid using WMI, but using get-counter often times didn't have the performance counter I wanted.

The solution I used was the Common Information Model (CIM). Unlike WMI, CIM doesn't use DCOM by default. Instead of returning WMI objects, CIM cmdlets return PowerShell objects.

CIM uses the Ws-MAN protocol by default, but it only works with computers that have access to Ws-Man 3.0 or later. So, earlier versions of PowerShell wouldn't be able to issue CIM cmdlets.

The cmdlet I ended up using to get total physical memory size was:

get-ciminstance -class "cim_physicalmemory" | % {$_.Capacity}

Changing SQL Server collation to case insensitive from case sensitive?

You can do that but the changes will affect for new data that is inserted on the database. On the long run follow as suggested above.

Also there are certain tricks you can override the collation, such as parameters for stored procedures or functions, alias data types, and variables are assigned the default collation of the database. To change the collation of an alias type, you must drop the alias and re-create it.

You can override the default collation of a literal string by using the COLLATE clause. If you do not specify a collation, the literal is assigned the database default collation. You can use DATABASEPROPERTYEX to find the current collation of the database.

You can override the server, database, or column collation by specifying a collation in the ORDER BY clause of a SELECT statement.

Select all occurrences of selected word in VSCode

I needed to extract all the matched search lines (using regex) in a file

  1. Ctrl+F Open find. Select regex icon and enter search pattern
  2. (optional) Enable select highlights by opening settings and search for selectHighlights (Ctrl+,, selectHighlights)
  3. Ctrl+L Select all search items
  4. Ctrl+C Copy all selected lines
  5. Ctrl+N Open new document
  6. Ctrl+V Paste all searched lines.

What are the differences between Mustache.js and Handlebars.js?

NOTE: This answer is outdated. It was true at the time it was posted, but no longer is.

Mustache has interpreters in many languages, while Handlebars is Javascript only.

How to play a notification sound on websites?

2021 solution

function playSound(url) {
  const audio = new Audio(url);;
<button onclick="playSound('https://your-file.mp3');">Play</button>  

Browser support

Edge 12+, Firefox 20+, Internet Explorer 9+, Opera 15+, Safari 4+, Chrome

Codecs Support

Just use MP3

Old solution

(for legacy browsers)

function playSound(filename){
  var mp3Source = '<source src="' + filename + '.mp3" type="audio/mpeg">';
  var oggSource = '<source src="' + filename + '.ogg" type="audio/ogg">';
  var embedSource = '<embed hidden="true" autostart="true" loop="false" src="' + filename +'.mp3">';
  document.getElementById("sound").innerHTML='<audio autoplay="autoplay">' + mp3Source + oggSource + embedSource + '</audio>';
<button onclick="playSound('bing');">Play</button>  
<div id="sound"></div>

Browser support

Codes used

  • MP3 for Chrome, Safari and Internet Explorer.
  • OGG for Firefox and Opera.

Adding maven nexus repo to my pom.xml

If you don't want or you cannot modify the settings.xml file, you can create a new one in your root project, and call maven passing it as a parameter with the -s parameter:

$ mvn COMMAND ... -s settings.xml

Writing handler for UIAlertAction

create alert, tested in xcode 9

let alert = UIAlertController(title: "title", message: "message", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.default, handler: self.finishAlert))
self.present(alert, animated: true, completion: nil)

and the function

func finishAlert(alert: UIAlertAction!)

How to remove square brackets from list in Python?

if you have numbers in list, you can use map to apply str to each element:

print ', '.join(map(str, LIST))

^ map is C code so it's faster than str(i) for i in LIST

Trying to mock, but not working

For what it's worth, the Mock docs talk about specifically, and it's possible to do this without having to create a dummy class:

>>> from datetime import date
>>> with patch('') as mock_date:
... = date(2010, 10, 8)
...     mock_date.side_effect = lambda *args, **kw: date(*args, **kw)
...     assert == date(2010, 10, 8)
...     assert, 6, 8) == date(2009, 6, 8)

Add legend to ggplot2 line plot

I really like the solution proposed by @Brian Diggs. However, in my case, I create the line plots in a loop rather than giving them explicitly because I do not know apriori how many plots I will have. When I tried to adapt the @Brian's code I faced some problems with handling the colors correctly. Turned out I needed to modify the aesthetic functions. In case someone has the same problem, here is the code that worked for me.

I used the same data frame as @Brian:

data <- structure(list(month = structure(c(1317452400, 1317538800, 1317625200, 1317711600, 
                                       1317798000, 1317884400, 1317970800, 1318057200, 
                                       1318143600, 1318230000, 1318316400, 1318402800, 
                                       1318489200, 1318575600, 1318662000, 1318748400, 
                                       1318834800, 1318921200, 1319007600, 1319094000), 
                                     class = c("POSIXct", "POSIXt"), tzone = ""),
                   TempMax = c(26.58, 27.78, 27.9, 27.44, 30.9, 30.44, 27.57, 25.71, 
                               25.98, 26.84, 33.58, 30.7, 31.3, 27.18, 26.58, 26.18, 
                               25.19, 24.19, 27.65, 23.92), 
                   TempMed = c(22.88, 22.87, 22.41, 21.63, 22.43, 22.29, 21.89, 20.52,
                                 19.71, 20.73, 23.51, 23.13, 22.95, 21.95, 21.91, 20.72, 
                                 20.45, 19.42, 19.97, 19.61), 
                   TempMin = c(19.34, 19.14, 18.34, 17.49, 16.75, 16.75, 16.88, 16.82, 
                               14.82, 16.01, 16.88, 17.55, 16.75, 17.22, 19.01, 16.95, 
                               17.55, 15.21, 14.22, 16.42)), 
              .Names = c("month", "TempMax", "TempMed", "TempMin"), 
              row.names = c(NA, 20L), class = "data.frame")  

In my case, I generate my.cols and my.names dynamically, but I don't want to make things unnecessarily complicated so I give them explicitly here. These three lines make the ordering of the legend and assigning colors easier.

my.cols <- heat.colors(3, alpha=1)
my.names <- c("TempMin", "TempMed", "TempMax")
names(my.cols) <- my.names

And here is the plot:

p <-  ggplot(data, aes(x = month))

for (i in 1:3){
  p <- p + geom_line(aes_(y =[i+1])), colour = 
p + scale_colour_manual("", 
                        breaks = as.character(my.names),
                        values = my.cols)

enter image description here

How to find out the location of currently used MySQL configuration file in linux

login to mysql with proper credential and used mysql>SHOW VARIABLES LIKE 'datadir'; that will give you path of where mysql stored

How to name variables on the fly?

Don't make data frames. Keep the list, name its elements but do not attach it.

The biggest reason for this is that if you make variables on the go, almost always you will later on have to iterate through each one of them to perform something useful. There you will again be forced to iterate through each one of the names that you have created on the fly.

It is far easier to name the elements of the list and iterate through the names.

As far as attach is concerned, its really bad programming practice in R and can lead to a lot of trouble if you are not careful.

Passing arrays as parameters in bash

As ugly as it is, here is a workaround that works as long as you aren't passing an array explicitly, but a variable corresponding to an array:

function passarray()
    eval array_internally=("$(echo '${'$1'[@]}')")
    # access array now via array_internally
    echo "${array_internally[@]}"

array=(0 1 2 3 4 5)
passarray array # echo's (0 1 2 3 4 5) as expected

I'm sure someone can come up with a clearner implementation of the idea, but I've found this to be a better solution than passing an array as "{array[@]"} and then accessing it internally using array_inside=("$@"). This becomes complicated when there are other positional/getopts parameters. In these cases, I've had to first determine and then remove the parameters not associated with the array using some combination of shift and array element removal.

A purist perspective likely views this approach as a violation of the language, but pragmatically speaking, this approach has saved me a whole lot of grief. On a related topic, I also use eval to assign an internally constructed array to a variable named according to a parameter target_varname I pass to the function:

eval $target_varname=$"(${array_inside[@]})"

Hope this helps someone.

Difference between "or" and || in Ruby?

It's a matter of operator precedence.

|| has a higher precedence than or.

So, in between the two you have other operators including ternary (? :) and assignment (=) so which one you choose can affect the outcome of statements.

Here's a ruby operator precedence table.

See this question for another example using and/&&.

Also, be aware of some nasty things that could happen:

a = false || true  #=> true
a  #=> true

a = false or true  #=> true
a  #=> false

Both of the previous two statements evaluate to true, but the second sets a to false since = precedence is lower than || but higher than or.

How to calculate the bounding box for a given lat/lng location?

Here is Federico Ramponi's answer in Go. Note: no error-checking :(

import (

// Semi-axes of WGS-84 geoidal reference
const (
    // Major semiaxis (meters)
    WGS84A = 6378137.0
    // Minor semiaxis (meters)
    WGS84B = 6356752.3

// BoundingBox represents the geo-polygon that encompasses the given point and radius
type BoundingBox struct {
    LatMin float64
    LatMax float64
    LonMin float64
    LonMax float64

// Convert a degree value to radians
func deg2Rad(deg float64) float64 {
    return math.Pi * deg / 180.0

// Convert a radian value to degrees
func rad2Deg(rad float64) float64 {
    return 180.0 * rad / math.Pi

// Get the Earth's radius in meters at a given latitude based on the WGS84 ellipsoid
func getWgs84EarthRadius(lat float64) float64 {
    an := WGS84A * WGS84A * math.Cos(lat)
    bn := WGS84B * WGS84B * math.Sin(lat)

    ad := WGS84A * math.Cos(lat)
    bd := WGS84B * math.Sin(lat)

    return math.Sqrt((an*an + bn*bn) / (ad*ad + bd*bd))

// GetBoundingBox returns a BoundingBox encompassing the given lat/long point and radius
func GetBoundingBox(latDeg float64, longDeg float64, radiusKm float64) BoundingBox {
    lat := deg2Rad(latDeg)
    lon := deg2Rad(longDeg)
    halfSide := 1000 * radiusKm

    // Radius of Earth at given latitude
    radius := getWgs84EarthRadius(lat)

    pradius := radius * math.Cos(lat)

    latMin := lat - halfSide/radius
    latMax := lat + halfSide/radius
    lonMin := lon - halfSide/pradius
    lonMax := lon + halfSide/pradius

    return BoundingBox{
        LatMin: rad2Deg(latMin),
        LatMax: rad2Deg(latMax),
        LonMin: rad2Deg(lonMin),
        LonMax: rad2Deg(lonMax),

ggplot combining two plots from different data.frames

As Baptiste said, you need to specify the data argument at the geom level. Either

#df1 is the default dataset for all geoms
(plot1 <- ggplot(df1, aes(v, p)) + 
    geom_point() +
    geom_step(data = df2)


#No default; data explicitly specified for each geom
(plot2 <- ggplot(NULL, aes(v, p)) + 
      geom_point(data = df1) +
      geom_step(data = df2)

How do you use the Immediate Window in Visual Studio?

The Immediate window is used to debug and evaluate expressions, execute statements, print variable values, and so forth. It allows you to enter expressions to be evaluated or executed by the development language during debugging.

To display Immediate Window, choose Debug >Windows >Immediate or press Ctrl-Alt-I

enter image description here

Here is an example with Immediate Window:

int Sum(int x, int y) { return (x + y);}
void main(){
int a, b, c;
a = 5;
b = 7;
c = Sum(a, b);
char temp = getchar();}

add breakpoint

enter image description here

call commands

enter image description here

Cannot use mkdir in home directory: permission denied (Linux Lubuntu)

you can try writing the command using 'sudo':

sudo mkdir DirName

Python: Assign Value if None Exists

Here is the easiest way I use, hope works for you,

var1 = var1 or 4

This assigns 4 to var1 only if var1 is None , False or 0

EditText non editable

android:editable="false" should work, but it is deprecated, you should be using android:inputType="none" instead.

Alternatively, if you want to do it in the code you could do this :

EditText mEdit = (EditText) findViewById(;

This is also a viable alternative :

EditText mEdit = (EditText) findViewById(;

If you're going to make your EditText non-editable, may I suggest using the TextView widget instead of the EditText, since using a EditText seems kind of pointless in that case.

EDIT: Altered some information since I've found that android:editable is deprecated, and you should use android:inputType="none", but there is a bug about it on android code; So please check this.

shell-script headers (#!/bin/sh vs #!/bin/csh)

This defines what shell (command interpreter) you are using for interpreting/running your script. Each shell is slightly different in the way it interacts with the user and executes scripts (programs).

When you type in a command at the Unix prompt, you are interacting with the shell.

E.g., #!/bin/csh refers to the C-shell, /bin/tcsh the t-shell, /bin/bash the bash shell, etc.

You can tell which interactive shell you are using the

 echo $SHELL

command, or alternatively

 env | grep -i shell

You can change your command shell with the chsh command.

Each has a slightly different command set and way of assigning variables and its own set of programming constructs. For instance the if-else statement with bash looks different that the one in the C-shell.

This page might be of interest as it "translates" between bash and tcsh commands/syntax.

Using the directive in the shell script allows you to run programs using a different shell. For instance I use the tcsh shell interactively, but often run bash scripts using /bin/bash in the script file.


This concept extends to other scripts too. For instance if you program in Python you'd put


at the top of your Python program

How to check a radio button with jQuery?

If property name does not work don't forget that id still exists. This answer is for people who wants to target the id here how you do.


Because property name does not work for me. Make sure you don't surround id and name with double/single quotations.


How to hide a button programmatically?

Kotlin code is a lot simpler:

if(isVisable) {
    clearButton.visibility = View.INVISIBLE
else {
    clearButton.visibility = View.VISIBLE

show dbs gives "Not Authorized to execute command" error

Copy of answer OP posted in question:


After the update from the previous edit, I looked a bit about the connection between client and server and I found out that even when mongod.exe was not running, there was still something listening on port 27017 with netstat -a

So I tried to launch the server with a random port using

[dir]mongod.exe --port 2000

Then the shell with

[dir]mongo.exe --port 2000

And this time, the server printed a message saying there is a new connection. I typed few commands and everything was working perfectly fine, I started the basic tutorial from the documentation to check if it was ok and for now it is.

How to call on a function found on another file?

Small addition to @user995502's answer on how to run the program.

g++ player.cpp main.cpp -o main.out && ./main.out

Git for beginners: The definitive practical guide

How to track remote branches

Assuming there is a remote repository that you cloned your local repository from and also assuming that there is a branch named 'some_branch' on that remote repository, here is how to track it locally:

# list remote branches
git branch -r

# start tracking one remote branch
git branch --track some_branch origin/some_branch

# change to the branch locally
git checkout some_branch

# make changes and commit them locally

# push your changes to the remote repository:
git push

Where does pip install its packages?

One can import the package then consult its help

import statsmodels

At the very bottom of the help there is a section FILE that indicates where this package was installed.

This solution was tested with at least matplotlib (3.1.2) and statsmodels (0.11.1) (python 3.8.2).

HTML5 image icon to input placeholder

Adding to Tim's answer:

  #search:placeholder-shown {
     // show background image, I like svg 
     // when using svg, do not use HEX for colour; you can use rbg/a instead
     // also notice the single quotes
     background-image url('data:image/svg+xml; utf8, <svg>... <g fill="grey"...</svg>')
     // other background props

   #search:not(:placeholder-shown) { background-image: none;}

c++ exception : throwing std::string

Though this question is rather old and has already been answered, I just want to add a note on how to do proper exception handling in C++11:

Use std::nested_exception and std::throw_with_nested

Using these, in my opinion, leads to cleaner exception design and makes it unnecessary to create an exception class hierarchy.

Note that this enables you to get a backtrace on your exceptions inside your code without need for a debugger or cumbersome logging. It is described on StackOverflow here and here, how to write a proper exception handler which will rethrow nested exceptions.

Since you can do this with any derived exception class, you can add a lot of information to such a backtrace! You may also take a look at my MWE on GitHub, where a backtrace would look something like this:

Library API: Exception caught in function 'api_function'
~/Git/mwe-cpp-exception/src/detail/Library.cpp:17 : library_function failed
~/Git/mwe-cpp-exception/src/detail/Library.cpp:13 : could not open file "nonexistent.txt"

How to stretch a table over multiple pages

You should \usepackage{longtable}.

java: ArrayList - how can I check if an index exists?

You can check the size of an ArrayList using the size() method. This will return the maximum index +1

Clicking a checkbox with ng-click does not update the model

It is kind of a hack but wrapping it in a timeout seems to accomplish what you are looking for:

angular.module('myApp', [])
    .controller('Ctrl', ['$scope', '$timeout', function ($scope, $timeout) {
    $scope.todos = [{
        'text': "get milk",
        'done': true
    }, {
        'text': "get milk2",
            'done': false

    $scope.onCompleteTodo = function (todo) {
            console.log("onCompleteTodo -done: " + todo.done + " : " + todo.text);
            $scope.doneAfterClick = todo.done;
            $scope.todoText = todo.text;

What is the use of static constructors?

Static constructor called only the first instance of the class created. and used to perform a particular action that needs to be performed only once in the life cycle of the class.

How to redirect to a different domain using NGINX?

That should work via HTTPRewriteModule.

Example rewrite from to

server {    
    rewrite ^$request_uri? permanent; 

How do I compile the asm generated by GCC?

Yes, You can use gcc to compile your asm code. Use -c for compilation like this:

gcc -c file.S -o file.o

This will give object code file named file.o. To invoke linker perform following after above command:

gcc file.o -o file

Why call super() in a constructor?

We can access super class elements by using super keyword

Consider we have two classes, Parent class and Child class, with different implementations of method foo. Now in child class if we want to call the method foo of parent class, we can do so by; we can also access parent elements by super keyword.

    class parent {
    String str="I am parent";
    //method of parent Class
    public void foo() {
        System.out.println("Hello World " + str);

class child extends parent {
    String str="I am child";
    // different foo implementation in child Class
    public void foo() {
        System.out.println("Hello World "+str);

    // calling the foo method of parent class
    public void parentClassFoo(){;

    // changing the value of str in parent class and calling the foo method of parent class
    public void parentClassFooStr(){
        super.str="parent string changed";;

public class Main{
        public static void main(String args[]) {
            child obj = new child();

How to convert an Stream into a byte[] in C#?

    byte[] buf;  // byte array
    Stream stream=Page.Request.InputStream;  //initialise new stream
    buf = new byte[stream.Length];  //declare arraysize
    stream.Read(buf, 0, buf.Length); // read from stream to byte array

Check OS version in Swift?

Note: Available in iOS 8.0 and later. OS X v10.10 and later

var majorVersion: Int    { return NSProcessInfo.processInfo().operatingSystemVersion.majorVersion }
var minorVersion: Int    { return NSProcessInfo.processInfo().operatingSystemVersion.minorVersion }
var patchVersion: Int    { return NSProcessInfo.processInfo().operatingSystemVersion.patchVersion }
var myOSVersion:  String { return NSProcessInfo.processInfo().operatingSystemVersionString        }

How to convert a Drawable to a Bitmap?

Here is better resolution

public static Bitmap drawableToBitmap (Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable)drawable).getBitmap();

    Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap); 
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());

    return bitmap;

public static InputStream bitmapToInputStream(Bitmap bitmap) {
    int size = bitmap.getHeight() * bitmap.getRowBytes();
    ByteBuffer buffer = ByteBuffer.allocate(size);
    return new ByteArrayInputStream(buffer.array());

Code from How to read drawable bits as InputStream

SQL Not Like Statement not working


Should work, do you get more rows if you run the same SQL with the "NOT LIKE" line commented out? If not, check the data. I know you mentioned in your question, but check that the actual SQL statement is using that clause. The other answers with NULL are also a good idea.

successful/fail message pop up box after submit?

You are echoing outside the body tag of your HTML. Put your echos there, and you should be fine.

Also, remove the onclick="alert()" from your submit. This is the cause for your first undefined message.

  $posted = false;
  if( $_POST ) {
    $posted = true;

    // Database stuff here...
    // $result = mysql_query( ... )
    $result = $_POST['name'] == "danny"; // Dummy result


    if( $posted ) {
      if( $result ) 
        echo "<script type='text/javascript'>alert('submitted successfully!')</script>";
        echo "<script type='text/javascript'>alert('failed!')</script>";
    <form action="" method="post">
      Name:<input type="text" id="name" name="name"/>
      <input type="submit" value="submit" name="submit"/>

Simple Digit Recognition OCR in OpenCV-Python

OCR which stands for Optical Character Recognition is a computer vision technique used to identify the different types of handwritten digits that are used in common mathematics. To perform OCR in OpenCV we will use the KNN algorithm which detects the nearest k neighbors of a particular data point and then classifies that data point based on the class type detected for n neighbors.

Data Used

This data contains 5000 handwritten digits where there are 500 digits for every type of digit. Each digit is of 20×20 pixel dimensions. We will split the data such that 250 digits are for training and 250 digits are for testing for every class.

Below is the implementation.

import numpy as np
import cv2
# Read the image
image = cv2.imread('digits.png')
# gray scale conversion
gray_img = cv2.cvtColor(image,
# We will divide the image
# into 5000 small dimensions 
# of size 20x20
divisions = list(np.hsplit(i,100) for i in np.vsplit(gray_img,50))
# Convert into Numpy array
# of size (50,100,20,20)
NP_array = np.array(divisions)
# Preparing train_data
# and test_data.
# Size will be (2500,20x20)
train_data = NP_array[:,:50].reshape(-1,400).astype(np.float32)
# Size will be (2500,20x20)
test_data = NP_array[:,50:100].reshape(-1,400).astype(np.float32)
# Create 10 different labels 
# for each type of digit
k = np.arange(10)
train_labels = np.repeat(k,250)[:,np.newaxis]
test_labels = np.repeat(k,250)[:,np.newaxis]
# Initiate kNN classifier
knn =
# perform training of data
# obtain the output from the
# classifier by specifying the
# number of neighbors.
ret, output ,neighbours,
distance = knn.findNearest(test_data, k = 3)
# Check the performance and
# accuracy of the classifier.
# Compare the output with test_labels
# to find out how many are wrong.
matched = output==test_labels
correct_OP = np.count_nonzero(matched)
#Calculate the accuracy.
accuracy = (correct_OP*100.0)/(output.size)
# Display accuracy.



Well, I decided to workout myself on my question to solve the above problem. What I wanted is to implement a simple OCR using KNearest or SVM features in OpenCV. And below is what I did and how. (it is just for learning how to use KNearest for simple OCR purposes).

1) My first question was about file that comes with OpenCV samples. I wanted to know what is inside that file.

It contains a letter, along with 16 features of that letter.

And this SOF helped me to find it. These 16 features are explained in the paper Letter Recognition Using Holland-Style Adaptive Classifiers. (Although I didn't understand some of the features at the end)

2) Since I knew, without understanding all those features, it is difficult to do that method. I tried some other papers, but all were a little difficult for a beginner.

So I just decided to take all the pixel values as my features. (I was not worried about accuracy or performance, I just wanted it to work, at least with the least accuracy)

I took the below image for my training data:

enter image description here

(I know the amount of training data is less. But, since all letters are of the same font and size, I decided to try on this).

To prepare the data for training, I made a small code in OpenCV. It does the following things:

  1. It loads the image.
  2. Selects the digits (obviously by contour finding and applying constraints on area and height of letters to avoid false detections).
  3. Draws the bounding rectangle around one letter and wait for key press manually. This time we press the digit key ourselves corresponding to the letter in the box.
  4. Once the corresponding digit key is pressed, it resizes this box to 10x10 and saves all 100 pixel values in an array (here, samples) and corresponding manually entered digit in another array(here, responses).
  5. Then save both the arrays in separate .txt files.

At the end of the manual classification of digits, all the digits in the training data (train.png) are labeled manually by ourselves, image will look like below:

enter image description here

Below is the code I used for the above purpose (of course, not so clean):

import sys

import numpy as np
import cv2

im = cv2.imread('pitrain.png')
im3 = im.copy()

gray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray,(5,5),0)
thresh = cv2.adaptiveThreshold(blur,255,1,1,11,2)

#################      Now finding Contours         ###################

contours,hierarchy = cv2.findContours(thresh,cv2.RETR_LIST,cv2.CHAIN_APPROX_SIMPLE)

samples =  np.empty((0,100))
responses = []
keys = [i for i in range(48,58)]

for cnt in contours:
    if cv2.contourArea(cnt)>50:
        [x,y,w,h] = cv2.boundingRect(cnt)
        if  h>28:
            roi = thresh[y:y+h,x:x+w]
            roismall = cv2.resize(roi,(10,10))
            key = cv2.waitKey(0)

            if key == 27:  # (escape to quit)
            elif key in keys:
                sample = roismall.reshape((1,100))
                samples = np.append(samples,sample,0)

responses = np.array(responses,np.float32)
responses = responses.reshape((responses.size,1))
print "training complete"


Now we enter in to training and testing part.

For the testing part, I used the below image, which has the same type of letters I used for the training phase.

enter image description here

For training we do as follows:

  1. Load the .txt files we already saved earlier
  2. create an instance of the classifier we are using (it is KNearest in this case)
  3. Then we use KNearest.train function to train the data

For testing purposes, we do as follows:

  1. We load the image used for testing
  2. process the image as earlier and extract each digit using contour methods
  3. Draw a bounding box for it, then resize it to 10x10, and store its pixel values in an array as done earlier.
  4. Then we use KNearest.find_nearest() function to find the nearest item to the one we gave. ( If lucky, it recognizes the correct digit.)

I included last two steps (training and testing) in single code below:

import cv2
import numpy as np

#######   training part    ############### 
samples = np.loadtxt('',np.float32)
responses = np.loadtxt('',np.float32)
responses = responses.reshape((responses.size,1))

model = cv2.KNearest()

############################# testing part  #########################

im = cv2.imread('pi.png')
out = np.zeros(im.shape,np.uint8)
gray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
thresh = cv2.adaptiveThreshold(gray,255,1,1,11,2)

contours,hierarchy = cv2.findContours(thresh,cv2.RETR_LIST,cv2.CHAIN_APPROX_SIMPLE)

for cnt in contours:
    if cv2.contourArea(cnt)>50:
        [x,y,w,h] = cv2.boundingRect(cnt)
        if  h>28:
            roi = thresh[y:y+h,x:x+w]
            roismall = cv2.resize(roi,(10,10))
            roismall = roismall.reshape((1,100))
            roismall = np.float32(roismall)
            retval, results, neigh_resp, dists = model.find_nearest(roismall, k = 1)
            string = str(int((results[0][0])))


And it worked, below is the result I got:

enter image description here

Here it worked with 100% accuracy. I assume this is because all the digits are of the same kind and the same size.

But anyway, this is a good start to go for beginners (I hope so).

Yii2 data provider default sorting

defaultOrder contain a array where key is a column name and value is a SORT_DESC or SORT_ASC that's why below code not working.

$dataProvider = new ActiveDataProvider([
        'query' => $query,
        'sort' => ['defaultOrder'=>'topic_order asc']

Correct Way

$dataProvider = new ActiveDataProvider([
    'query' => $query,
    'sort' => [
        'defaultOrder' => [
            'topic_order' => SORT_ASC,

Note: If a query already specifies the orderBy clause, the new ordering instructions given by end users (through the sort configuration) will be appended to the existing orderBy clause. Any existing limit and offset clauses will be overwritten by the pagination request from end users (through the pagination configuration).

You can detail learn from Yii2 Guide of Data Provider

Sorting By passing Sort object in query

 $sort = new Sort([
        'attributes' => [
            'name' => [
                'asc' => ['first_name' => SORT_ASC, 'last_name' => SORT_ASC],
                'desc' => ['first_name' => SORT_DESC, 'last_name' => SORT_DESC],
                'default' => SORT_DESC,
                'label' => 'Name',

    $models = Article::find()
        ->where(['status' => 1])

How Exactly Does @param Work - Java

It is basically a comment. As we know, a number of people working on the same project must have knowledge about the code changes. We are making some notes in the program about the parameters.

TortoiseGit-git did not exit cleanly (exit code 1)

For My case i did 3 steps to achieve the sucessful build.

  1. revert all the local changes if any (or just keep a copy of it in case you need it for future use)

  2. Do a git clean up, do a pull and check the logs for error

  3. GO to the git bash option and the error i was getting in log in above stem (i my case ) as "error: cannot lock ref and the branch details", so in the git bash i ran the following command git update-ref -d 'Branch_name'

For example if the error was something like **


**error: cannot lock ref 'refs/remotes/origin/EXMPLEISSUE/EXAMPLE-1011_DEMO_web_interface_DOES_NOT_GET_GIT_UPDATE':

Then i ran following command git update-ref -d 'refs/remotes/origin/EXMPLEISSUE/EXAMPLE-1011_DEMO_web_interface_DOES_NOT_GET_GIT_UPDATE'

We have to ensure all the error in logs to be solved similarly before getting a successful pull by doing git update-ref -d 'Branch_name' and finally i can get the take the successful pull from git.

Is there a sleep function in JavaScript?

If you are looking to block the execution of code with call to sleep, then no, there is no method for that in JavaScript.

JavaScript does have setTimeout method. setTimeout will let you defer execution of a function for x milliseconds.

setTimeout(myFunction, 3000);

// if you have defined a function named myFunction 
// it will run after 3 seconds (3000 milliseconds)

Remember, this is completely different from how sleep method, if it existed, would behave.

function test1()
    // let's say JavaScript did have a sleep function..
    // sleep for 3 seconds


If you run the above function, you will have to wait for 3 seconds (sleep method call is blocking) before you see the alert 'hi'. Unfortunately, there is no sleep function like that in JavaScript.

function test2()
    // defer the execution of anonymous function for 
    // 3 seconds and go to next line of code.

    }, 3000);  


If you run test2, you will see 'hi' right away (setTimeout is non blocking) and after 3 seconds you will see the alert 'hello'.

Non-static method requires a target

Normally it happens when the target is null. So better check the invoke target first then do the linq query.

How can I make Bootstrap columns all the same height?


**Bootstrap 4 Equal Height Solution **

Bootstrap Utilities/flex for equal height

Live example in Codepen

Equal height by bootstrap class with parent div fixed height or min-height

<div class="d-flex align-content-stretch flex-wrap" style="min-height: 200px">
    <div>Flex height test text for example , Flex height test text for example </div>
    <div>Flex item</div>
    <div>Flex item</div>
    <div>Flex item</div>

.bd-highlight {_x000D_
    background-color: rgba(86,61,124,.15);_x000D_
    border: 1px solid rgba(86,61,124,.15);_x000D_
.fixed-height-200 {_x000D_
  min-height: 200px;_x000D_
<link href="" rel="stylesheet"/>_x000D_
<div class="d-flex align-content-stretch flex-wrap fixed-height-200">_x000D_
    <div class="p-2 bd-highlight">Flex item <br> 1111111111</div>_x000D_
    <div class="p-2 bd-highlight bg-danger">Flex item</div>_x000D_
    <div class="p-2 bd-highlight">Flex item</div>_x000D_
    <div class="p-2 bd-highlight bg-info">Flex item</div>_x000D_
    <div class="p-2 bd-highlight">Flex item</div>_x000D_
    <div class="p-2 bd-highlight">Flex item</div>_x000D_
    <div class="p-2 bd-highlight bg-light">Flex item <br> 1111111111</div>_x000D_
    <div class="p-2 bd-highlight">Flex item <br> 1111111111</div>_x000D_
    <div class="p-2 bd-highlight">Flex item <br> 1111111111</div>_x000D_
    <div class="p-2 bd-highlight">Flex item</div>_x000D_
    <div class="p-2 bd-highlight bg-primary">Flex item</div>_x000D_
    <div class="p-2 bd-highlight">Flex item</div>_x000D_
    <div class="p-2 bd-highlight">Flex item</div>_x000D_
    <div class="p-2 bd-highlight">Flex item</div>_x000D_
    <div class="p-2 bd-highlight">Flex item</div>_x000D_

How to Find Item in Dictionary Collection?

Sometimes you still need to use FirstOrDefault if you have to do different tests. If the Key component of your dictionnary is nullable, you can do this:

thisTag = _tags.FirstOrDefault(t => t.Key.SubString(1,1) == 'a');
if(thisTag.Key != null) { ... }

Using FirstOrDefault, the returned KeyValuePair's key and value will both be null if no match is found.

What is the use of the init() usage in JavaScript?

JavaScript doesn't have a built-in init() function, that is, it's not a part of the language. But it's not uncommon (in a lot of languages) for individual programmers to create their own init() function for initialisation stuff.

A particular init() function may be used to initialise the whole webpage, in which case it would probably be called from document.ready or onload processing, or it may be to initialise a particular type of object, or...well, you name it.

What any given init() does specifically is really up to whatever the person who wrote it needed it to do. Some types of code don't need any initialisation.

function init() {
  // initialisation stuff here

// elsewhere in code

date() method, "A non well formed numeric value encountered" does not want to format a date passed in $_POST

From the documentation for strtotime():

Dates in the m/d/y or d-m-y formats are disambiguated by looking at the separator between the various components: if the separator is a slash (/), then the American m/d/y is assumed; whereas if the separator is a dash (-) or a dot (.), then the European d-m-y format is assumed.

In your date string, you have 12-16-2013. 16 isn't a valid month, and hence strtotime() returns false.

Since you can't use DateTime class, you could manually replace the - with / using str_replace() to convert the date string into a format that strtotime() understands:

$date = '2-16-2013';
echo date('Y-m-d', strtotime(str_replace('-','/', $date))); // => 2013-02-16

ServletException, HttpServletResponse and HttpServletRequest cannot be resolved to a type

You can do the folllwoing: import the jar file inside you class:

import javax.servlet.http.HttpServletResponse

add the Apache Tomcat library as follow:

Project > Properties > Java Build Path > Libraries > Add library from library tab > Choose server runtime > Next > choose Apache Tomcat v 6.0 > Finish > Ok

Also First of all, make sure that Servlet jar is included in your class path in eclipse as PermGenError said.

I think this will solve your error

How can I use ":" as an AWK field separator?

"-F" is a command line argument, not AWK syntax. Try:

 echo "1: " | awk -F  ":" '/1/ {print $1}'

Short IF - ELSE statement

I'm a little late to the party but for future readers.

From what i can tell, you're just wanting to toggle the visibility state right? Why not just use the ! operator?


It's not an if statement but I prefer this method for code related to your example.

What is sr-only in Bootstrap 3?

As JoshC said, the class .sr-only is used to visually hide the information used for screen readers only. But not only to hide labels. You might consider hiding various other elements such as "skip to main content" link, icons which have an alternative texts etc.

BTW. you can also use .sr-only sr-only-focusable if you need the element to become visible when focused e.g. "skip to main content"

If you want make your website even more accessible I recommend to start here:


According to the World Health Organization, 285 million people have vision impairments. So making a website accessible is important.

IMPORTANT: Avoid treating disabled users differently. Generally speaking try to avoid developing a different content for different groups of users. Instead try to make accessible the existing content so that it simply works out-of-the-box and for all not specifically targeting e.g. screen readers. In other words don't try to reinvent the wheel. Otherwise the resulting accessibility will often be worse than if there was nothing developed at all. We developers should not assume how those users will use our website. So be very careful when you need to develop such solutions. Obviously a "skip link" is a good example of such content if it's made visible when focused. But there many bad examples too. Such would be hiding from a screen reader a "zoom" button on the map assuming that it has no relevance to blind users. But surprisingly, a zoom function indeed is used among blind users! They like to download images like many other users do (even in high resolution), for sending them to somebody else or for using them in some other context. Source - Read more @ADG: Bad ARIA practices

Setting onSubmit in React.js

I'd also suggest moving the event handler outside render.

var OnSubmitTest = React.createClass({

  submit: function(e){
    alert('it works!');

  render: function() {
    return (
      <form onSubmit={this.submit}>
        <button>Click me</button>

How do I get a python program to do nothing?

You could use a pass statement:

if condition:

Python 2.x documentation

Python 3.x documentation

However I doubt you want to do this, unless you just need to put something in as a placeholder until you come back and write the actual code for the if statement.

If you have something like this:

if condition:        # condition in your case being `num2 == num5`

You can in general change it to this:

if not condition:

But in this specific case you could (and should) do this:

if num2 != num5:        # != is the not-equal-to operator

Usage of sys.stdout.flush() method

import sys
for x in range(10000):
    print "HAPPY >> %s <<\r" % str(x),

How do I put a border around an Android textview?

The simple way is to add a view for your TextView. Example for the bottom border line:

<LinearLayout android:orientation="vertical"


For the other direction borders, please adjust the location of the separator view.

In Laravel, the best way to pass different types of flash messages in the session

One solution would be to flash two variables into the session:

  1. The message itself
  2. The "class" of your alert

for example:

Session::flash('message', 'This is a message!'); 
Session::flash('alert-class', 'alert-danger'); 

Then in your view:

<p class="alert {{ Session::get('alert-class', 'alert-info') }}">{{ Session::get('message') }}</p>

Note I've put a default value into the Session::get(). that way you only need to override it if the warning should be something other than the alert-info class.

(that is a quick example, and untested :) )

Access Database opens as read only

While the OP is the original author of the database, and likely created a simple data model, I had experienced a similar behavior on a more complicated system. In my scenario the main .mdb file was on a network share location with read/write access by the user. The .mdb file referenced tables in another .mdb file in a different network location - where the user did not have proper access.

For others viewing this post to solve similar problems, verify the linked tables path and access.

To verify linked tables...(assuming Access 2010)

  1. Open database
  2. Click ribbon toolbar tab 'External Data'
  3. Click ribbon toolbar button 'Linked Table Manager'
  4. Identify paths to linked tables
  5. Verify proper security clearance to paths identified in linked table manager - if accessing ODBC (i.e., Oracle, DB2, MySql, PostGRES, etc.) sources, verify database credentials and drivers

Iterate through a HashMap


for (String key : hashMap.keySet()) {
    System.out.println("Key: " + key + ", Value: " + map.get(key));

How to pass boolean values to a PowerShell script from a command prompt

This is an older question, but there is actually an answer to this in the PowerShell documentation. I had the same problem, and for once RTFM actually solved it. Almost.

Documentation for the -File parameter states that "In rare cases, you might need to provide a Boolean value for a switch parameter. To provide a Boolean value for a switch parameter in the value of the File parameter, enclose the parameter name and value in curly braces, such as the following: -File .\Get-Script.ps1 {-All:$False}"

I had to write it like this:

PowerShell.Exe -File MyFile.ps1 {-SomeBoolParameter:False}

So no '$' before the true/false statement, and that worked for me, on PowerShell 4.0

How do I convert a IPython Notebook into a Python file via commandline?

Jupytext is nice to have in your toolchain for such conversions. It allows not only conversion from a notebook to a script, but you can go back again from the script to notebook as well. And even have that notebook produced in executed form.

jupytext --to py notebook.ipynb                 # convert notebook.ipynb to a .py file
jupytext --to notebook              # convert to an .ipynb file with no outputs
jupytext --to notebook --execute    # convert to an .ipynb file and run it 

How do I run Visual Studio as an administrator by default?

Copied and pasted from here, the Using Advanced Properties section. This will allow you to always have the program run as an administrator when you open it.

Windows 7:

  1. Right click on the shortcut of the program, then click on Properties.
  2. Click on the Shortcut tab for a program shortcut, then click on the Advanced button.
  3. Check the 'Run as administrator' box, and click on OK.
  4. Click on OK.
  5. Open the program.
  6. If prompted by UAC, then click on Yes to apply permission to allow the program to run with full permission as an Administrator.

NOTE: If you are doing this is while logged in as standard user instead of an administrator, then you will need to provide the administrator's password before the program will run as administrator.

Update: (2015-07-05)

Windows 8, 8.1 and 10

In Windows 8, you have to right-click devenv.exe and select "Troubleshoot compatibility".

  1. Select "Troubleshoot program"

  2. Check "The program requires additional permissions" click "Next", click "Test the program..."

  3. Wait for the program to launch

  4. Click "Next"

  5. Select "Yes, save these settings for this program"

  6. Click "Close"

Update reference original Link

HTML list-style-type dash

Here is my fiddle version:

The (modernizr) class .generatedcontent on <html> practically means IE8+ and every other sane browser.

<html class="generatedcontent">
  <ul class="ul-dash hanging">
    <li>Lorem ipsum dolor sit amet stack o verflow dot com</li>
    <li>Lorem ipsum dolor sit amet stack o verflow dot com</li>


.ul-dash {
  margin: 0;

.ul-dash {
  margin-left: 0em;
  padding-left: 1.5em;

.ul-dash.hanging > li { /* remove '>' for IE6 support */
  padding-left: 1em;
  text-indent: -1em;

.generatedcontent .ul-dash {
  list-style: none;
.generatedcontent .ul-dash > li:before {
  content: "–";
  text-indent: 0;
  display: inline-block;
  width: 0;
  position: relative;
  left: -1.5em;

Command to get nth line of STDOUT

Yes, the most efficient way (as already pointed out by Jonathan Leffler) is to use sed with print & quit:

set -o pipefail                        # cf. help set
time -p ls -l | sed -n -e '2{p;q;}'    # only print the second line & quit (on Mac OS X)
echo "$?: ${PIPESTATUS[*]}"            # cf. man bash | less -p 'PIPESTATUS'

Checking if a variable is initialized

Variable that is not defined will cause compilation error.

What you're asking is about checking if it is initialized. But initialization is just a value, that you should choose and assign in the constructor.

For example:

class MyClass
    MyClass() : mCharacter('0'), mDecimal(-1.0){};
    void SomeMethod();

    char mCharacter;
    double mDecimal;

void MyClass::SomeMethod()
    if ( mCharacter != '0')
        // touched after the constructor
        // do something with mCharacter.

    if ( mDecimal != -1.0 )
        // touched after the constructor
        // define mDecimal.

You should initialize to a default value that will mean something in the context of your logic, of course.

Android Shared preferences for creating one time activity (example)

Shared Preferences is so easy to learn, so take a look on this simple tutorial about sharedpreference

import android.os.Bundle;
import android.preference.PreferenceActivity;

    public class UserSettingActivity extends PreferenceActivity {

    public void onCreate(Bundle savedInstanceState) {



Webview load html from assets directory

Download source code from here (Open html file from assets android)


<RelativeLayout xmlns:android=""


package com.deepshikha.htmlfromassets;
 import android.os.Bundle;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;

public class MainActivity extends AppCompatActivity {

WebView webview;
 ProgressDialog progressDialog;

 protected void onCreate(Bundle savedInstanceState) {

private void init(){
 webview = (WebView)findViewById(;

progressDialog = new ProgressDialog(MainActivity.this);

webview.setWebViewClient(new WebViewClient() {

public void onPageFinished(WebView view, String url) {
 try {
 } catch (Exception e) {

replacing text in a file with Python

The essential way is

  • read(),
  • data = data.replace() as often as you need and then
  • write().

If you read and write the whole data at once or in smaller parts is up to you. You should make it depend on the expected file size.

read() can be replaced with the iteration over the file object.

How to force JS to do math instead of putting two strings together

After trying most of the answers here without success for my particular case, I came up with this:

dots = -(-dots - 5);

The + signs are what confuse js, and this eliminates them entirely. Simple to implement, if potentially confusing to understand.

How to quickly and conveniently disable all console.log statements in my code?

I found a little more advanced piece of code in this url JavaScript Tip: Bust and Disable console.log:

var DEBUG_MODE = true; // Set this value to false for production

if(typeof(console) === 'undefined') {
   console = {}

if(!DEBUG_MODE || typeof(console.log) === 'undefined') {
   // FYI: Firebug might get cranky...
   console.log = console.error = = console.debug = console.warn = console.trace = console.dir = console.dirxml = = console.groupEnd = console.time =    console.timeEnd = console.assert = console.profile = function() {};


Following the steps mentioned above for =>3.0 for Debug mode

urlpatterns = [
+ static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

And also the part that caught me out, the above static URL only worked in my main project file. I was first attempting to add to my app, and wondering why I couldn't see the images.

Lastly make sure you set the following:

MEDIA_ROOT = os.path.join(BASE_DIR, 'media')
MEDIA_URL = '/media/'

How to suppress Update Links warning?


After all the details summarized and discussed, I spent 2 fair hours in checking the options, and this update is to dot all is.


First of all, I performed a clean Office 2010 x86 install on Clean Win7 SP1 Ultimate x64 virtual machine powered by VMWare (this is usual routine for my everyday testing tasks, so I have many of them deployed).

Then, I changed only the following Excel options (i.e. all the other are left as is after installation):

  • Advanced > General > Ask to update automatic links checked:

Ask to update automatic links

  • Trust Center > Trust Center Settings... > External Content > Enable All... (although that one that relates to Data Connections is most likely not important for the case):

External Content


I prepared and placed to C:\ a workbook exactly as per @Siddharth Rout suggestions in his updated answer (shared for your convenience): Linked book was then deleted so that link in the shared book is unavailable (for sure).

Manual Opening

The above shared file shows on opening (having the above listed Excel options) 2 warnings - in the order of appearance:


This workbook contains links to other data sources

After click on Update I expectedly got another:


This workbook contains one or more links that cannot be updated

So, I suppose my testing environment is now pretty much similar to OP's) So far so good, we finally go to

VBA Opening

Now I'll try all possible options step by step to make the picture clear. I'll share only relevant lines of code for simplicity (complete sample file with code will be shared in the end).

1. Simple Application.Workbooks.Open

Application.Workbooks.Open Filename:="C:\Book1withLinkToBook2.xlsx"

No surprise - this produces BOTH warnings, as for manual opening above.

2. Application.DisplayAlerts = False

Application.DisplayAlerts = False
Application.Workbooks.Open Filename:="C:\Book1withLinkToBook2.xlsx"
Application.DisplayAlerts = True

This code ends up with WARNING #1, and either option clicked (Update / Don't Update) produces NO further warnings, i.e. Application.DisplayAlerts = False suppresses WARNING #2.

3. Application.AskToUpdateLinks = False

Application.AskToUpdateLinks = False
Application.Workbooks.Open Filename:="C:\Book1withLinkToBook2.xlsx"
Application.AskToUpdateLinks = True

Opposite to DisplayAlerts, this code ends up with WARNING #2 only, i.e. Application.AskToUpdateLinks = False suppresses WARNING #1.

4. Double False

Application.AskToUpdateLinks = False
Application.DisplayAlerts = False
Application.Workbooks.Open Filename:="C:\Book1withLinkToBook2.xlsx"
Application.DisplayAlerts = True
Application.AskToUpdateLinks = True

Apparently, this code ends up with suppressing BOTH WARNINGS.

5. UpdateLinks:=False

Application.Workbooks.Open Filename:="C:\Book1withLinkToBook2.xlsx", UpdateLinks:=False

Finally, this 1-line solution (originally proposed by @brettdj) works the same way as Double False: NO WARNINGS are shown!


Except a good testing practice and very important solved case (I may face such issues everyday while sending my workbooks to 3rd party, and now I'm prepared), 2 more things learned:

  1. Excel options DO matter, regardless of version - especially when we come to VBA solutions.
  2. Every trouble has short and elegant solution - together with not obvious and complicated one. Just one more proof for that!)

Thanks very much to everyone who contributed to the solution, and especially OP who raised the question. Hope my investigations and thoroughly described testing steps were helpful not only for me)

Sample file with the above code samples is shared (many lines are commented deliberately):

Original answer (tested for Excel 2007 with certain options):

This code works fine for me - it loops through ALL Excel files specified using wildcards in the InputFolder:

Sub WorkbookOpening2007()

Dim InputFolder As String
Dim LoopFileNameExt As String

InputFolder = "D:\DOCUMENTS\" 'Trailing "\" is required!

LoopFileNameExt = Dir(InputFolder & "*.xls?")
Do While LoopFileNameExt <> ""

Application.DisplayAlerts = False
Application.Workbooks.Open (InputFolder & LoopFileNameExt)
Application.DisplayAlerts = True

LoopFileNameExt = Dir

End Sub

I tried it with books with unavailable external links - no warnings.

Sample file:

How can JavaScript save to a local file?

While most despise Flash, it is a viable option for providing "save" and "save as" functionality in your html/javascript environment.

I've created a widget called "OpenSave" that provides this functionality available here:


QuotaExceededError: Dom exception 22: An attempt was made to add something to storage that exceeded the quota

As mentioned in other answers, you'll always get the QuotaExceededError in Safari Private Browser Mode on both iOS and OS X when localStorage.setItem (or sessionStorage.setItem) is called.

One solution is to do a try/catch or Modernizr check in each instance of using setItem.

However if you want a shim that simply globally stops this error being thrown, to prevent the rest of your JavaScript from breaking, you can use this:

// Safari, in Private Browsing Mode, looks like it supports localStorage but all calls to setItem
// throw QuotaExceededError. We're going to detect this and just silently drop any calls to setItem
// to avoid the entire page breaking, without having to do a check at each usage of Storage.
if (typeof localStorage === 'object') {
    try {
        localStorage.setItem('localStorage', 1);
    } catch (e) {
        Storage.prototype._setItem = Storage.prototype.setItem;
        Storage.prototype.setItem = function() {};
        alert('Your web browser does not support storing settings locally. In Safari, the most common cause of this is using "Private Browsing Mode". Some settings may not save or some features may not work properly for you.');

MySQL DELETE FROM with subquery as condition

For others that find this question looking to delete while using a subquery, I leave you this example for outsmarting MySQL (even if some people seem to think it cannot be done):

FROM tableE e
             FROM tableE
             WHERE arg = 1 AND foo = 'bar');

will give you an error:

ERROR 1093 (HY000): You can't specify target table 'e' for update in FROM clause

However this query:

FROM tableE e
             FROM (SELECT id
                   FROM tableE
                   WHERE arg = 1 AND foo = 'bar') x);

will work just fine:

Query OK, 1 row affected (3.91 sec)

Wrap your subquery up in an additional subquery (here named x) and MySQL will happily do what you ask.

How to view the SQL queries issued by JPA?

During explorative development, and to focus the SQL debugging logging on the specific method I want to check, I decorate that method with the following logger statements:

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import ch.qos.logback.classic.Level;

((ch.qos.logback.classic.Logger) LoggerFactory.getLogger("org.hibernate.SQL")).setLevel(Level.DEBUG);
entityManager.find(Customer.class, customerID);
((ch.qos.logback.classic.Logger) LoggerFactory.getLogger("org.hibernate.SQL")).setLevel(Level.INFO);

How to make a local variable (inside a function) global

If you need access to the internal states of a function, you're possibly better off using a class. You can make a class instance behave like a function by making it a callable, which is done by defining __call__:

class StatefulFunction( object ):
    def __init__( self ):
        self.public_value = 'foo'

    def __call__( self ):
        return self.public_value

>> f = StatefulFunction()
>> f()
>> f.public_value = 'bar'
>> f()

How to save as a new file and keep working on the original one in Vim?

The following command will create a copy in a new window. So you can continue see both original file and the new file.

:w {newfilename} | sp #

Confusing "duplicate identifier" Typescript error message

remove this @types/express-validator from package.json file, then run npm install

Read More

Author message: This package has been deprecated This is a stub types definition for express-validator ( express-validator provides its own type definitions, so you don't need @types/express-validator installed!

Table columns, setting both min and max width with css

Tables work differently; sometimes counter-intuitively.

The solution is to use width on the table cells instead of max-width.

Although it may sound like in that case the cells won't shrink below the given width, they will actually.
with no restrictions on c, if you give the table a width of 70px, the widths of a, b and c will come out as 16, 42 and 12 pixels, respectively.
With a table width of 400 pixels, they behave like you say you expect in your grid above.
Only when you try to give the table too small a size (smaller than a.min+b.min+the content of C) will it fail: then the table itself will be wider than specified.

I made a snippet based on your fiddle, in which I removed all the borders and paddings and border-spacing, so you can measure the widths more accurately.

table {_x000D_
  width: 70px;_x000D_
table, tbody, tr, td {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
  border: 0;_x000D_
  border-spacing: 0;_x000D_
.a, .c {_x000D_
  background-color: red;_x000D_
.b {_x000D_
  background-color: #F77;_x000D_
.a {_x000D_
  min-width: 10px;_x000D_
  width: 20px;_x000D_
  max-width: 20px;_x000D_
.b {_x000D_
  min-width: 40px;_x000D_
  width: 45px;_x000D_
  max-width: 45px;_x000D_
.c {}
    <td class="a">A</td>_x000D_
    <td class="b">B</td>_x000D_
    <td class="c">C</td>_x000D_
_x000D_ page without a code behind

There are two very different types of pages in SharePoint: Application Pages and Site Pages.

If you are going to use your page as an Application Page, you can safely use inline code or code behind in your page, as Application pages live on the file system.

If it's going to be a Site page, you can safely write inline code as long as you have it like that in the initial deployment. However if your site page is going to be customized at some point in the future, the inline code will no longer work because customized site pages live in the database and are executed in's "no compile" mode.

Bottom line is - you can write aspx pages with inline code. The only problem is with customized Site pages... which will no longer care for your inline code.

How do I use a 32-bit ODBC driver on 64-bit Server 2008 when the installer doesn't create a standard DSN?

It turns out that you can create 32-bit ODBC connections using C:\Windows\SysWOW64\odbcad32.exe. My solution was to create the 32-bit ODBC connection as a System DSN. This still didn't allow me to connect to it since .NET couldn't look it up. After significant and fruitless searching to find how to get the OdbcConnection class to look for the DSN in the right place, I stumbled upon a web site that suggested modifying the registry to solve a different problem.

I ended up creating the ODBC connection directly under HKLM\Software\ODBC. I looked in the SysWOW6432 key to find the parameters that were set up using the 32-bit version of the ODBC administration tool and recreated this in the standard location. I didn't add an entry for the driver, however, as that was not installed by the standard installer for the app either.

After creating the entry (by hand), I fired up my windows service and everything was happy.

Calling javascript function in iframe

Instead of getting the frame from the document, try getting the frame from the window object.

in the above example change this:

if (typeof (document.all.resultFrame.Reset) == "function")
    alert("resultFrame.Reset NOT found");


if (typeof (window.frames[0].Reset) == "function")
    alert("resultFrame.Reset NOT found");

the problem is that the scope of the javascript inside the iframe is not exposed through the DOM element for the iframe. only window objects contain the javascript scoping information for the frames.

Add space between HTML elements only using CSS

span:not(:last-child) {
    margin-right: 10px;

How do I populate a JComboBox with an ArrayList?

I believe you can create a new Vector using your ArrayList and pass that to the JCombobox Constructor.

JComboBox<String> combobox = new JComboBox<String>(new Vector<String>(myArrayList));

my example is only strings though.

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.

How to display an unordered list in two columns?

Though I found Gabriel answer to work to a degree i did find the following when trying to order the list vertically (first ul A-D and second ul E-G):

  • When the ul had an even number of li's in it, it was not evenly spreading it across the ul's
  • using the data-column in the ul didn't seem to work very well, I had to put 4 for 3 columns and even then it was still only spreading the li's into 2 of the ul generated by the JS

I have revised the JQuery so the above hopefully doesn't happen.

(function ($) {
    var initialContainer = $('.customcolumns'),
        columnItems = $('.customcolumns li'),
        columns = null,
        column = 0;
    function updateColumns() {
        column = 0;
        columnItems.each(function (idx, el) {
            if ($(columns.get(column)).find('li').length >= (columnItems.length /'columns'))) {
                column += 1;
    function setupColumns() {
        while (column++ <'columns')) {
        columns = $('.customcolumns');

.customcolumns {
  float: left;
  position: relative;
  margin-right: 20px;
<script src=""></script>
  <ul class="customcolumns" data-columns="3">

Update MySQL using HTML Form and PHP

Your sql is incorrect.

$sql = mysql_query("UPDATE anstalld....


$sql = "UPDATE anstalld...

Unable to Cast from Parent Class to Child Class

To cast, the actual object must be of a Type equal to or derived from the Type you are attempting to cast to...

or, to state it in the opposite way, the Type you are trying to cast it to must be the same as, or a base class of, the actual type of the object.

if your actual object is of type Baseclass, then you can't cast it to a derived class Type...

filter items in a python dictionary where keys contain a specific string

Jonathon gave you an approach using dict comprehensions in his answer. Here is an approach that deals with your do something part.

If you want to do something with the values of the dictionary, you don't need a dictionary comprehension at all:

I'm using iteritems() since you tagged your question with

results = map(some_function, [(k,v) for k,v in a_dict.iteritems() if 'foo' in k])

Now the result will be in a list with some_function applied to each key/value pair of the dictionary, that has foo in its key.

If you just want to deal with the values and ignore the keys, just change the list comprehension:

results = map(some_function, [v for k,v in a_dict.iteritems() if 'foo' in k])

some_function can be any callable, so a lambda would work as well:

results = map(lambda x: x*2, [v for k,v in a_dict.iteritems() if 'foo' in k])

The inner list is actually not required, as you can pass a generator expression to map as well:

>>> map(lambda a: a[0]*a[1], ((k,v) for k,v in {2:2, 3:2}.iteritems() if k == 2))

Calling Oracle stored procedure from C#?

Connecting to Oracle is ugly. Here is some cleaner code with a using statement. A lot of the other samples don't call the IDisposable Methods on the objects they create.

using (OracleConnection connection = new OracleConnection("ConnectionString"))
    using (OracleCommand command = new OracleCommand("ProcName", connection))             
          command.CommandType = CommandType.StoredProcedure;
          command.Parameters.Add("ParameterName", OracleDbType.Varchar2).Value = "Your Data Here";
          command.Parameters.Add("SomeOutVar", OracleDbType.Varchar2, 120);
          command.Parameters["return_out"].Direction = ParameterDirection.Output;
          command.Parameters.Add("SomeOutVar1", OracleDbType.Varchar2, 120);
          command.Parameters["return_out2"].Direction = ParameterDirection.Output;
          string SomeOutVar = command.Parameters["SomeOutVar"].Value.ToString();
          string SomeOutVar1 = command.Parameters["SomeOutVar1"].Value.ToString();

Creating a blurring overlay view

enter image description here

From Xcode you can do it easily. Follow the steps from xcode. Drage visual effect view on your uiview or imageview.

Happy Coding :)

update one table with data from another

Use the following block of query to update Table1 with Table2 based on ID:

UPDATE Table1, Table2 
SET Table1.DataColumn= Table2.DataColumn
where Table1.ID= Table2.ID;

This is the easiest and fastest way to tackle this problem.

Check which element has been clicked with jQuery

Use this, I think I can get your idea.

Live demo:

$('body').click(function(e) {

    var target = $(, article;

    if ('#news_gallery li .over')) {
       article = $('#news-article .news-article');
    } else if ('#work_gallery li .over')) {
       article = $('#work-article .work-article');
    } else if ('#search-item li')) {
       article = $('#search-item .search-article');

    if (article) {
       // Do Something

MySQL Workbench: How to keep the connection alive

In 5.2.47 (at least on mac), go the location of the preferences is: MySQLWorkbench->Preferences->SQL Editor

Then you'll see both:

DBMS connection keep-alive interval (in seconds): DBMS connection read time out (in seconds):

The latter is where you'll want to up the limit from 600 to something a bit more.

Transposing a 1D NumPy array

Another solution.... :-)

import numpy as np

a = [1,2,4]

[1, 2, 4]

b = np.array([a]).T

array([[1], [2], [4]])

How to redirect to a 404 in Rails?

You could also use the render file:

render file: "#{Rails.root}/public/404.html", layout: false, status: 404

Where you can choose to use the layout or not.

Another option is to use the Exceptions to control it:

raise ActiveRecord::RecordNotFound, "Record not found."

How to overwrite files with Copy-Item in PowerShell

Robocopy is designed for reliable copying with many copy options, file selection restart, etc.

/xf to excludes files and /e for subdirectories:

robocopy $copyAdmin $AdminPath /e /xf "web.config" "Deploy"

converting a javascript string to a html object

var s = '<div id="myDiv"></div>';
var htmlObject = document.createElement('div');
htmlObject.innerHTML = s;
htmlObject.getElementById("myDiv").style.marginTop = something;

How to compare binary files to check if they are the same?

My favourite ones using xxd hex-dumper from the vim package :

1) using vimdiff (part of vim)

vimdiff <( xxd "$FILE1" ) <( xxd "$FILE2" )

2) using diff

diff -W 140 -y <( xxd $FILE1 ) <( xxd $FILE2 ) | colordiff | less -R -p '  \|  '

How to turn NaN from parseInt into 0 for an empty string?

Also this way, why not write a function and call it where ever required . I'm assuming it's the entry into the form fields to perform calculations.

var Nanprocessor = function (entry) {
    if(entry=="NaN") {
        return 0;
    } else {
        return entry;

 outputfield.value = Nanprocessor(x); 

// where x is a value that is collected from a from field
// i.e say x =parseInt(formfield1.value); 

what's wrong doing this?