Programs & Examples On #Code patching

Click event on select option element in chrome

Since $(this) isn't correct anymore with ES6 arrow function which don't have have the same this than function() {}, you shouldn't use $( this ) if you use ES6 syntax.
Besides according to the official jQuery's anwser, there's a simpler way to do that what the top answer says.
The best way to get the html of a selected option is to use

$('#yourSelect option:selected').html();

You can replace html() by text() or anything else you want (but html() was in the original question).
Just add the event listener change, with the jQuery's shorthand method change(), to trigger your code when the selected option change.

 $ ('#yourSelect' ).change(() => {
    process($('#yourSelect option:selected').html());

If you just want to know the value of the option:selected (the option that the user has chosen) you can just use $('#yourSelect').val()

The declared package does not match the expected package ""

Eclipse expects the declared package to match the directory hierarchy - so it's expecting your Java file to be in a directory called "Devices" under your source root. At the moment it looks like the file is directly in your source root. So create the appropriate directory, and move the file in there.

Note that conventionally, packages are in lower case and include your organization name in reverse DNS order, e.g.;

How to change ProgressBar's progress indicator color in Android

I copied this from one of my apps, so there's prob a few extra attributes, but should give you the idea. This is from the layout that has the progress bar:

    android:progressDrawable="@drawable/greenprogress" />

Then create a new drawable with something similar to the following (In this case greenprogress.xml):

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="">
    <item android:id="@android:id/background">
            <corners android:radius="5dip" />
                android:startColor="#ff9d9e9d" />

    <item android:id="@android:id/secondaryProgress">
                <corners android:radius="5dip" />
                    android:startColor="#80ffd300" />
    <item android:id="@android:id/progress">
                <corners android:radius="5dip" />
                    android:startColor="#33FF33" />


You can change up the colors as needed, this will give you a green progress bar.

Selector on background color of TextView

Benoit's solution works, but you really don't need to incur the overhead to draw a shape. Since colors can be drawables, just define a color in a /res/values/colors.xml file:

<?xml version="1.0" encoding="utf-8"?>
    <color name="semitransparent_white">#77ffffff</color>

And then use as such in your selector:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="">
        android:drawable="@color/semitransparent_white" />

How to select a single column with Entity Framework?

You can use LINQ's .Select() to do that. In your case it would go something like:

string Name = yourDbContext
  .Where(u => u.UserId == 1)
  .Select(u => u.Name)
  .SingleOrDefault(); // This is what actually executes the request and return a response

If you are expecting more than one entry in response, you can use .ToList() instead, to execute the request. Something like this, to get the Name of everyone with age 30:

string[] Names = yourDbContext
  .Where(u => u.Age == 30)
  .Select(u => u.Name)

How to use XPath in Python?

You can use:


from xml.dom.ext.reader import Sax2
from xml import xpath
doc = Sax2.FromXmlFile('foo.xml').documentElement
for url in xpath.Evaluate('//@Url', doc):
  print url.value


import libxml2
doc = libxml2.parseFile('foo.xml')
for url in doc.xpathEval('//@Url'):
  print url.content

Superscript in CSS only?

Honestly I don't see the point in doing superscript/subscript in CSS only. There's no handy CSS attribute for it, just a bunch of homegrown implementations including:

.superscript { position: relative; top: -0.5em; font-size: 80%; }

or using vertical-align or I'm sure other ways. Thing is, it starts to get complicated:

The second point is worth emphasizing. Typically superscript/subscript is not actually a styling issue but is indicative of meaning.

Side note: It's worth mentioning this list of entities for common mathematical superscript and subscript expressions even though this question doesn't relate to that.

The sub/sup tags are in HTML and XHTML. I would just use those.

As for the rest of your CSS, the :after pseudo-element and content attributes are not widely supported. If you really don't want to put this manually in the HTML I think a Javascript-based solution is your next best bet. With jQuery this is as simple as:

$(function() {

Spring Boot: Cannot access REST Controller on localhost (404)

Adding to MattR's answer:

As stated in here, @SpringBootApplication automatically inserts the needed annotations: @Configuration, @EnableAutoConfiguration, and also @ComponentScan; however, the @ComponentScan will only look for the components in the same package as the App, in this case your com.nice.application, whereas your controller resides in com.nice.controller. That's why you get 404 because the App didn't find the controller in the application package.

java collections - keyset() vs entrySet() in map

Every call to the moves the iterator to the next element. If you want to use the current element in more than one statement or expression, you have to store it in a local variable. Or even better, why don't you simply use a for-each loop?

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

Moreover, loop over the entrySet is faster, because you don't query the map twice for each key. Also Map.Entry implementations usually implement the toString() method, so you don't have to print the key-value pair manually.

for (Entry<String, Integer> entry : map.entrySet()) {

fatal: could not create work tree dir 'kivy'

sudo chmod 777 DIR_NAME
git clone

should work fine

React fetch data in server before render

As a supplement of the answer of Michael Parker, you can make getData accept a callback function to active the setState update the data:

componentWillMount : function () {
    var data = this.getData(()=>this.setState({data : data}));

Why is 1/1/1970 the "epoch time"?


The earliest versions of Unix time had a 32-bit integer incrementing at a rate of 60 Hz, which was the rate of the system clock on the hardware of the early Unix systems. The value 60 Hz still appears in some software interfaces as a result. The epoch also differed from the current value. The first edition Unix Programmer's Manual dated November 3, 1971 defines the Unix time as "the time since 00:00:00, Jan. 1, 1971, measured in sixtieths of a second".

Javascript Array.sort implementation?

The ECMAscript standard does not specify which sort algorithm is to be used. Indeed, different browsers feature different sort algorithms. For example, Mozilla/Firefox's sort() is not stable (in the sorting sense of the word) when sorting a map. IE's sort() is stable.

How do I convert a C# List<string[]> to a Javascript array?

Many of these answers do work, but I have found the easiest way by far is to send data through ViewData or ViewBag and let JSON.Net serialize it.

I use this technique when Javascript is needed for HTML generation before the page load or when AJAX overhead needs to be avoided:

In the controller:

public ActionResult MyController()
    var addresses = myAddressesGetter();
    ViewData["addresses"] = addresses ;
    return View();

In the view:

@section scripts {
<script type="text/javascript">
    var MyjavascriptAddresses: @Html.Raw(JsonConvert.SerializeObject(ViewData["addresses"])),

You can always rely on JSON.NET whereas some browsers have poor JSON deserialization support. Another benefit over some methods in that you can see the Javascript using your browser's View --> Source, since it is simply text generated server-side.

Note that In most situations, Web API a more elegant way to get JSON to the client.

How to close Browser Tab After Submitting a Form?

If you have to use the same page as the action, you cannot use onSubmit="window.close();" as it will close the window before the response is received. You have to dinamycally output a JS snippet that closes the window after the SQL data is processed. It would however be far more elegant to use another page as the form action.

How to hide navigation bar permanently in android activity?


This is for Android 4.4+

Try out immersive mode

Fast snippet (for an Activity class):

private int currentApiVersion;

protected void onCreate(Bundle savedInstanceState)

    currentApiVersion = android.os.Build.VERSION.SDK_INT;

    final int flags = View.SYSTEM_UI_FLAG_LAYOUT_STABLE

    // This work only for android 4.4+
    if(currentApiVersion >= Build.VERSION_CODES.KITKAT)


        // Code below is to handle presses of Volume up or Volume down.
        // Without this, after pressing volume buttons, the navigation bar will
        // show up and won't hide
        final View decorView = getWindow().getDecorView();
            .setOnSystemUiVisibilityChangeListener(new View.OnSystemUiVisibilityChangeListener()

                public void onSystemUiVisibilityChange(int visibility)
                    if((visibility & View.SYSTEM_UI_FLAG_FULLSCREEN) == 0)


public void onWindowFocusChanged(boolean hasFocus)
    if(currentApiVersion >= Build.VERSION_CODES.KITKAT && hasFocus)
                | View.SYSTEM_UI_FLAG_FULLSCREEN
                | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);

If you have problems when you press Volume up or Volume down that your navigation bar show. I added code in onCreate see setOnSystemUiVisibilityChangeListener

Here is another related question:

Immersive mode navigation becomes sticky after volume press or minimise-restore

How can I insert binary file data into a binary SQL field using a simple insert statement?

If you mean using a literal, you simply have to create a binary string:

insert into Files (FileId, FileData) values (1, 0x010203040506)

And you will have a record with a six byte value for the FileData field.

You indicate in the comments that you want to just specify the file name, which you can't do with SQL Server 2000 (or any other version that I am aware of).

You would need a CLR stored procedure to do this in SQL Server 2005/2008 or an extended stored procedure (but I'd avoid that at all costs unless you have to) which takes the filename and then inserts the data (or returns the byte string, but that can possibly be quite long).

In regards to the question of only being able to get data from a SP/query, I would say the answer is yes, because if you give SQL Server the ability to read files from the file system, what do you do when you aren't connected through Windows Authentication, what user is used to determine the rights? If you are running the service as an admin (God forbid) then you can have an elevation of rights which shouldn't be allowed.

How to disable mouse right click on a web page?

It's unprofessional, anyway this will work with javascript enabled:

document.oncontextmenu = document.body.oncontextmenu = function() {return false;}

You may also want to show a message to the user before returning false.

However I have to say that this should not be done generally because it limits users options without resolving the issue (in fact the context menu can be very easily enabled again.).

The following article better explains why this should not be done and what other actions can be taken to solve common related issues:

How to download a file from my server using SSH (using PuTTY on Windows)

OpenSSH has been added to Windows as of autumn 2018, and is included in Windows 10 and Windows Server 2019.

So you can use it in command prompt or power shell like bellow.

C:\Users\Parsa>scp [email protected]:/etc/cassandra/cassandra.yaml F:\Temporary
[email protected]'s password:
cassandra.yaml                                  100%   66KB  71.3KB/s   00:00


(I know this question is pretty old now but this can be helpful for newcomers to this question)

how to emulate "insert ignore" and "on duplicate key update" (sql merge) with postgresql?

To get the insert ignore logic you can do something like below. I found simply inserting from a select statement of literal values worked best, then you can mask out the duplicate keys with a NOT EXISTS clause. To get the update on duplicate logic I suspect a pl/pgsql loop would be necessary.

INSERT INTO manager.vin_manufacturer
  ('935',' Citroën Brazil','Citroën'),
  ('ABC', 'Toyota', 'Toyota'),
  ('ZOM',' OM','OM')
  ) as tmp (vin_manufacturer_id, manufacturer_desc, make_desc)
    --ignore anything that has already been inserted
    SELECT 1 FROM manager.vin_manufacturer m where m.vin_manufacturer_id = tmp.vin_manufacturer_id)

PHP: Limit foreach() statement?

In PHP 5.5+, you can do

function limit($iterable, $limit) {
    foreach ($iterable as $key => $value) {
        if (!$limit--) break;
        yield $key => $value;

foreach (limit($arr, 10) as $key => $value) {
    // do stuff

Generators rock.

Random row selection in Pandas dataframe

With pandas version 0.16.1 and up, there is now a DataFrame.sample method built-in:

import pandas

df = pandas.DataFrame(

# Randomly sample 70% of your dataframe
df_percent = df.sample(frac=0.7)

# Randomly sample 7 elements from your dataframe
df_elements = df.sample(n=7)

For either approach above, you can get the rest of the rows by doing:

df_rest = df.loc[~df.index.isin(df_percent.index)]

String is immutable. What exactly is the meaning?

If some object bar holds a reference to a mutable object foo and encapsulates some of its state in mutable aspects of foo's state, that will allow code which can change those aspects of foo to change the corresponding aspects of bar's state without actually touching bar or even knowing of its existence. Generally, this means that objects which encapsulate their own state using mutable objects must ensure that no references to those objects are exposed to any code which might unexpectedly mutate them. By contrast, if bar holds a reference to an object moo and only uses immutable aspects of moo other than identity to encapsulate its state, then bar can freely expose moo to outside code without worrying about anything the outside code might do to it.

How to specify the bottom border of a <tr>?

tr td 
    border-bottom: 2px solid silver;

or if you want the border inside the TR tag, you can do this:

tr td {
    box-shadow: inset 0px -2px 0px silver;

HTML: How to center align a form

simple way:Add a "center" tag before the form tag

pip is not able to install packages correctly: Permission denied error

It looks like you're having a permissions error, based on this message in your output: error: could not create '/lib/python2.7/site-packages/lxml': Permission denied.

One thing you can try is doing a user install of the package with pip install lxml --user. For more information on how that works, check out this StackOverflow answer. (Thanks to Ishaan Taylor for the suggestion)

You can also run pip install as a superuser with sudo pip install lxml but it is not generally a good idea because it can cause issues with your system-level packages.

How to read string from keyboard using C?

You need to have the pointer to point somewhere to use it.

Try this code:

char word[64];
scanf("%s", word);

This creates a character array of lenth 64 and reads input to it. Note that if the input is longer than 64 bytes the word array overflows and your program becomes unreliable.

As Jens pointed out, it would be better to not use scanf for reading strings. This would be safe solution.

char word[64]
fgets(word, 63, stdin);
word[63] = 0;

How to add double quotes to a string that is inside a variable?

In C# you can use:

 string1 = @"Your ""Text"" Here";
 string2 = "Your \"Text\" Here";

What are carriage return, linefeed, and form feed?

On old paper-printer terminals, advancing to the next line involved two actions: moving the print head back to the beginning of the horizontal scan range (carriage return) and advancing the roll of paper being printed on (line feed).

Since we no longer use paper-printer terminals, those actions aren't really relevant anymore, but the characters used to signal them have stuck around in various incarnations.

How do I improve ASP.NET MVC application performance?

Following are things to do

  1. Kernel mode Cache
  2. Pipeline mode
  3. Remove unused modules
  4. runAllManagedModulesForAllRequests
  5. Don't write in wwwroot
  6. Remove unused view engines and language

Using variables inside a bash heredoc

In answer to your first question, there's no parameter substitution because you've put the delimiter in quotes - the bash manual says:

The format of here-documents is:


No parameter expansion, command substitution, arithmetic expansion, or pathname expansion is performed on word. If any characters in word are quoted, the delimiter is the result of quote removal on word, and the lines in the here-document are not expanded. If word is unquoted, all lines of the here-document are subjected to parameter expansion, command substitution, and arithmetic expansion. [...]

If you change your first example to use <<EOF instead of << "EOF" you'll find that it works.

In your second example, the shell invokes sudo only with the parameter cat, and the redirection applies to the output of sudo cat as the original user. It'll work if you try:

sudo sh -c "cat > /path/to/outfile" <<EOT
my text...

How to find all serial devices (ttyS, ttyUSB, ..) on Linux without opening them?

I do not have a USB serial device, but there must be a way to find the real ports using the HAL libraries directly:

#! /usr/bin/env bash
# Uses HAL to find existing serial hardware

for sport in $(hal-find-by-capability --capability serial) ; do
  hal-get-property --udi "${sport}" --key serial.device


The posted python-dbus code nor this sh script lists the bluetooth /dev/rfcomm* devices, so it is not the best solution.

Note that on other unix platforms, the serial ports are not named ttyS? and even in linux, some serial cards allow you to name the devices. Assuming a pattern in the serial devices names is wrong.

How can I show/hide a specific alert with twitter bootstrap?

You can simply use id(#)selector like this.


How to add checkboxes to JTABLE swing

1) JTable knows JCheckbox with built-in Boolean TableCellRenderers and TableCellEditor by default, then there is contraproductive declare something about that,

2) AbstractTableModel should be useful, where is in the JTable required to reduce/restrict/change nested and inherits methods by default implemented in the DefaultTableModel,

3) consider using DefaultTableModel, (if you are not sure about how to works) instead of AbstractTableModel,


could be generated from simple code:

import javax.swing.*;
import javax.swing.table.*;

public class TableCheckBox extends JFrame {

    private static final long serialVersionUID = 1L;
    private JTable table;

    public TableCheckBox() {
        Object[] columnNames = {"Type", "Company", "Shares", "Price", "Boolean"};
        Object[][] data = {
            {"Buy", "IBM", new Integer(1000), new Double(80.50), false},
            {"Sell", "MicroSoft", new Integer(2000), new Double(6.25), true},
            {"Sell", "Apple", new Integer(3000), new Double(7.35), true},
            {"Buy", "Nortel", new Integer(4000), new Double(20.00), false}
        DefaultTableModel model = new DefaultTableModel(data, columnNames);
        table = new JTable(model) {

            private static final long serialVersionUID = 1L;

            public Class getColumnClass(int column) {
            return getValueAt(0, column).getClass();
            public Class getColumnClass(int column) {
                switch (column) {
                    case 0:
                        return String.class;
                    case 1:
                        return String.class;
                    case 2:
                        return Integer.class;
                    case 3:
                        return Double.class;
                        return Boolean.class;
        JScrollPane scrollPane = new JScrollPane(table);

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            public void run() {
                TableCheckBox frame = new TableCheckBox();
                frame.setLocation(150, 150);

How to install Boost on Ubuntu

Install libboost-all-dev by entering the following commands in the terminal

Step 1

Update package repositories and get latest package information.

sudo apt update -y

Step 2

Install the packages and dependencies with -y flag .

sudo apt install -y libboost-all-dev

Now that you have your libboost-all-dev installed source:

What is the use of the JavaScript 'bind' method?


The bind() method takes an object as an first argument and creates a new function. When the function is invoked the value of this in the function body will be the object which was passed in as an argument in the bind() function.

How does this work in JS anyway

The value of this in javascript is dependent always depends on what Object the function is called. The value of this always refers to the object left of the dot from where is the function is called. In case of the global scope this is window (or global in nodeJS). Only call, apply and bind can alter the this binding differently. Here is an example to show how the this keyword works:

let obj = {_x000D_
  prop1: 1,_x000D_
  func: function () { console.log(this); } _x000D_
obj.func();   // obj left of the dot so this refers to obj_x000D_
const customFunc = obj.func;  // we store the function in the customFunc obj_x000D_
customFunc();  // now the object left of the dot is window, _x000D_
               // customFunc() is shorthand for window.customFunc()_x000D_
               // Therefore window will be logged

How is bind used?

Bind can help in overcoming difficulties with the this keyword by having a fixed object where this will refer to. For example:

var name = 'globalName';_x000D_
const obj = {_x000D_
  name: 'myName',_x000D_
  sayName: function () { console.log(;}_x000D_
const say = obj.sayName; // we are merely storing the function the value of this isn't magically transferred_x000D_
say(); // now because this function is executed in global scope this will refer to the global var_x000D_
const boundSay = obj.sayName.bind(obj); // now the value of this is bound to the obj object_x000D_
boundSay();  // Now this will refer to the name in the obj object: 'myName'

Once the function is bound to a particular this value we can pass it around and even put it on properties on other objects. The value of this will remain the same.

Adding values to a C# array

Answers on how to do it using an array are provided here.

However, C# has a very handy thing called System.Collections :)

Collections are fancy alternatives to using an array, though many of them use an array internally.

For example, C# has a collection called List that functions very similar to the PHP array.

using System.Collections.Generic;

// Create a List, and it can only contain integers.
List<int> list = new List<int>();

for (int i = 0; i < 400; i++)

How to add a new row to datagridview programmatically

If you need to manipulate anything aside from the Cell Value string such as adding a Tag, try this:

DataGridViewRow newRow = (DataGridViewRow)mappingDataGridView.RowTemplate.Clone();

newRow.Cells[0].Value = mapping.Key;
newRow.Cells[1].Value = ((BusinessObject)mapping.Value).Name;
newRow.Cells[1].Tag = mapping.Value;


How to use OAuth2RestTemplate?

In the answer from @mariubog ( I was using password grant types too as in the example but needed to set the client authentication scheme to form. Scopes were not supported by the endpoint for password and there was no need to set the grant type as the ResourceOwnerPasswordResourceDetails object sets this itself in the constructor.


public ResourceOwnerPasswordResourceDetails() {


The key thing for me was the client_id and client_secret were not being added to the form object to post in the body if resource.setClientAuthenticationScheme(AuthenticationScheme.form); was not set.

See the switch in:

Finally, when connecting to Salesforce endpoint the password token needed to be appended to the password.

class MyConfig {

private String tokenUrl;

private String clientId;

private String clientSecret;

private String passwordToken;

private String username;

private String password;

protected OAuth2ProtectedResourceDetails resource() {

    ResourceOwnerPasswordResourceDetails resource = new ResourceOwnerPasswordResourceDetails();

    resource.setPassword(password + passwordToken);

    return resource;

 public OAuth2RestOperations restTemplate() {
    return new OAuth2RestTemplate(resource(), new DefaultOAuth2ClientContext(new DefaultAccessTokenRequest()));

class MyService {
    private OAuth2RestOperations restTemplate;

    public MyService() {

Is background-color:none valid CSS?

CSS Level 3 specifies the unset property value. From MDN:

The unset CSS keyword is the combination of the initial and inherit keywords. Like these two other CSS-wide keywords, it can be applied to any CSS property, including the CSS shorthand all. This keyword resets the property to its inherited value if it inherits from its parent or to its initial value if not. In other words, it behaves like the inherit keyword in the first case and like the initial keyword in the second case.

Unfortunately this value is currently not supported in all browsers, including IE, Safari and Opera. I suggest using transparent for the time being.

Github: Can I see the number of downloads for a repo?

GitHub has deprecated the download support and now supports 'Releases' - To create a release either use the GitHub UI or create an annotated tag (http:// and add release notes to it in GitHub. You can then upload binaries, or 'assets', to each release.

Once you have some releases, the GitHub API supports getting information about them, and their assets.

curl -i \ \
-H "Accept: application/vnd.github.manifold-preview+json"

Look for the 'download_count' entry. Theres more info at This part of the API is still in the preview period ATM so it may change.

Update Nov 2013:

GitHub's releases API is now out of the preview period so the 'Accept' header is no longer needed -

It won't do any harm to continue to add the 'Accept' header though.

How to reset the state of a Redux store?

 const reducer = (state = initialState, { type, payload }) => {

   switch (type) {
      case RESET_STORE: {
        state = initialState

   return state

You can also fire an action which is handled by all or some reducers, that you want to reset to initial store. One action can trigger a reset to your whole state, or just a piece of it that seems fit to you. I believe this is the simplest and most controllable way of doing this.

How do I check in python if an element of a list is empty?

Just check if that element is equal to None type or make use of NOT operator ,which is equivalent to the NULL type you observe in other languages.

if not A[i]:
    ## do whatever

Anyway if you know the size of your list then you don't need to do all this.

Is there a way to make mv create the directory to be moved to if it doesn't exist?

mkdir -p `dirname /destination/moved_file_name.txt`  
mv /full/path/the/file.txt  /destination/moved_file_name.txt

MySQL error 2006: mysql server has gone away

MAMP 5.3, you will not find my.cnf and adding them does not work as that max_allowed_packet is stored in variables.

One solution can be:

  1. Go to http://localhost/phpmyadmin
  2. Go to SQL tab
  3. Run SHOW VARIABLES and check the values, if it is small then run with big values
  4. Run the following query, it set max_allowed_packet to 7gb:

    set global max_allowed_packet=268435456;

For some, you may need to increase the following values as well:

set global wait_timeout = 600;
set innodb_log_file_size =268435456;

What's the best way to build a string of delimited items in Java?

For those who are in a Spring context their StringUtils class is useful as well:

There are many useful shortcuts like:

  • collectionToCommaDelimitedString(Collection coll)
  • collectionToDelimitedString(Collection coll, String delim)
  • arrayToDelimitedString(Object[] arr, String delim)

and many others.

This can be helpful if you are not already using Java 8 and you are already in a Spring context.

I prefer it against the Apache Commons (although very good as well) for the Collection support which is easier like this:

// Encoding Set<String> to String delimited 
String asString = org.springframework.util.StringUtils.collectionToDelimitedString(codes, ";");

// Decoding String delimited to Set
Set<String> collection = org.springframework.util.StringUtils.commaDelimitedListToSet(asString);

The type java.lang.CharSequence cannot be resolved in package declaration

Just trying to compile with ant, Have same error when using org.eclipse.jdt.core-3.5.2.v_981_R35x.jar, Everything is well after upgrade to org.eclipse.jdt.core_3.10.2.v20150120-1634.jar

Kill all processes for a given user

The following kills all the processes created by this user:

kill  -9  -1

How to make zsh run as a login shell on Mac OS X (in iTerm)?

In iTerm -> Preferences -> Profiles Tab -> General section set Command to: /bin/zsh --login

/bin/zsh --login

How to check if a column exists before adding it to an existing table in PL/SQL?

Normally, I'd suggest trying the ANSI-92 standard meta tables for something like this but I see now that Oracle doesn't support it.

-- this works against most any other database
    C.COLUMN_NAME = 'columnname'
    AND T.TABLE_NAME = 'tablename'

Instead, it looks like you need to do something like

-- Oracle specific table/column query
    TABLE_NAME = 'tablename'
    AND COLUMN_NAME = 'columnname'

I do apologize in that I don't have an Oracle instance to verify the above. If it does not work, please let me know and I will delete this post.

C# How can I check if a URL exists/is valid?

Here is another implementation of this solution:

using System.Net;

/// Checks the file exists or not.
/// The URL of the remote file.
/// True : If the file exits, False if file not exists
private bool RemoteFileExists(string url)
        //Creating the HttpWebRequest
        HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
        //Setting the Request method HEAD, you can also use GET too.
        request.Method = "HEAD";
        //Getting the Web Response.
        HttpWebResponse response = request.GetResponse() as HttpWebResponse;
        //Returns TRUE if the Status code == 200
        return (response.StatusCode == HttpStatusCode.OK);
        //Any exception will returns false.
        return false;


How to catch integer(0)?

You can easily catch integer(0) with function identical(x,y)

x = integer(0)
identical(x, integer(0))
[1] TRUE

foo = function(x){identical(x, integer(0))}
[1] TRUE


how to remove json object key and value.?

There are several ways to do this, lets see them one by one:

  1. delete method: The most common way

const myObject = {_x000D_
    "employeeid": "160915848",_x000D_
    "firstName": "tet",_x000D_
    "lastName": "test",_x000D_
    "email": "[email protected]",_x000D_
    "country": "Brasil",_x000D_
    "currentIndustry": "aaaaaaaaaaaaa",_x000D_
    "otherIndustry": "aaaaaaaaaaaaa",_x000D_
    "currentOrganization": "test",_x000D_
    "salary": "1234567"_x000D_
delete myObject['currentIndustry'];_x000D_
// OR delete myObject.currentIndustry;_x000D_

  1. By making key value undefined: Alternate & a faster way:

let myObject = {_x000D_
    "employeeid": "160915848",_x000D_
    "firstName": "tet",_x000D_
    "lastName": "test",_x000D_
    "email": "[email protected]",_x000D_
    "country": "Brasil",_x000D_
    "currentIndustry": "aaaaaaaaaaaaa",_x000D_
    "otherIndustry": "aaaaaaaaaaaaa",_x000D_
    "currentOrganization": "test",_x000D_
    "salary": "1234567"_x000D_
myObject.currentIndustry = undefined;_x000D_
myObject = JSON.parse(JSON.stringify(myObject));_x000D_

  1. With es6 spread Operator:

const myObject = {_x000D_
    "employeeid": "160915848",_x000D_
    "firstName": "tet",_x000D_
    "lastName": "test",_x000D_
    "email": "[email protected]",_x000D_
    "country": "Brasil",_x000D_
    "currentIndustry": "aaaaaaaaaaaaa",_x000D_
    "otherIndustry": "aaaaaaaaaaaaa",_x000D_
    "currentOrganization": "test",_x000D_
    "salary": "1234567"_x000D_
const {currentIndustry, ...filteredObject} = myObject;_x000D_

Or if you can use omit() of underscore js library:

const filteredObject = _.omit(currentIndustry, 'myObject');

When to use what??

If you don't wanna create a new filtered object, simply go for either option 1 or 2. Make sure you define your object with let while going with the second option as we are overriding the values. Or else you can use any of them.

hope this helps :)

Div not expanding even with content inside

There are two solutions to fix this:

  1. Use clear:both after the last floated tag. This works good.
  2. If you have fixed height for your div or clipping of content is fine, go with: overflow: hidden

Deck of cards JAVA

Here is some code. It uses 2 classes ( and to accomplish this issue, and to top it off it auto sorts it for you when you create the deck object. :)

import java.util.*;

public class deck2 {
    ArrayList<Card> cards = new ArrayList<Card>();

    String[] values = {"A","2","3","4","5","6","7","8","9","10","J","Q","K"};
    String[] suit = {"Club", "Spade", "Diamond", "Heart"};

    static boolean firstThread = true;
    public deck2(){
        for (int i = 0; i<suit.length; i++) {
            for(int j=0; j<values.length; j++){
        //shuffle the deck when its created


    public ArrayList<Card> getDeck(){
        return cards;

    public static void main(String[] args){
        deck2 deck = new deck2();

        //print out the deck.


//separate class

public class Card {

    private String suit;
    private String value;

    public Card(String suit, String value){
        this.suit = suit;
        this.value = value;
    public Card(){}
    public String getSuit(){
        return suit;
    public void setSuit(String suit){
        this.suit = suit;
    public String getValue(){
        return value;
    public void setValue(String value){
        this.value = value;

    public String toString(){
        return "\n"+value + " of "+ suit;

How to connect to my http://localhost web server from Android Emulator

I do not know, maybe this topic is already solved, but when I have tried recently do this on Windows machine, I have faced with lot of difficulties. So my solution was really simple. I have downloaded this soft followed their instructions about how to make port forwarding and then successfully my android device connected to make localhost project and stopped on my breaking point.

my rinetd.conf file: 1234 1234 82 82

Where is my localhost ip, 82 and 1234 my ports Also I have craeted bath file for easy life yournameofbathfile.bat, put that file inside rinedfolder. My bath file:

rinetd.exe -c rinetd.conf

After starting this soft, start your server and try to access from android device or any device in your local network(for example Computer ABC starts putty) and you will see that everything works. No need to go to router setting or do any other complicated things. I hope this will help you. Enjoy.

Getting result of dynamic SQL into a variable for sql-server

You've probably tried this, but are your specifications such that you can do this?

DECLARE @city varchar(75)
SET @city = 'London'
SELECT @count = COUNT(*) FROM customers WHERE City = @city

Getting a better understanding of callback functions in JavaScript

the proper implementation would be:

if( callback ) callback();

this makes the callback parameter optional..

Checking if a date is valid in javascript

Try this:

var date = new Date();
console.log(date instanceof Date && !isNaN(date.valueOf()));

This should return true.

UPDATED: Added isNaN check to handle the case commented by Julian H. Lam

String split on new line, tab and some number of spaces

>>> for line in s.splitlines():
...     line = line.strip()
...     if not line:continue
...     ary.append(line.split(":"))
>>> ary
[['Name', ' John Smith'], ['Home', ' Anytown USA'], ['Misc', ' Data with spaces'
>>> dict(ary)
{'Home': ' Anytown USA', 'Misc': ' Data with spaces', 'Name': ' John Smith'}

How to write the Fibonacci Sequence?

Doing this solution by calling function and modularized

def userInput():
    number = int(input('Please enter the number between 1 - 40 to find out the 
    fibonacci :'))
    return number

def findFibonacci(number):
    if number == 0:
        return 0
    elif number == 1:
        return 1
        return findFibonacci(number - 1) + findFibonacci (number - 2)

def main():
    userNumber = userInput()


How to set cellpadding and cellspacing in table with CSS?

Here is the solution.


<table cellspacing="0" cellpadding="0">

The CSS:

table { 

Hope this helps.


td, th {padding:0}

How to set iframe size dynamically

The height is different depending on the browser's window size. It should be set dynamically depending on the size of the browser window

<!DOCTYPE html>
    <iframe src="url" height="600" width="1350" title="Enter Here"></iframe>

jquery: change the URL address without redirecting?

That site makes use of the "fragment" part of a url: the stuff after the "#". This is not sent to the server by the browser as part of the GET request, but can be used to store page state. So yes you can change the fragment without causing a page refresh or reload. When the page loads, your javascript reads this fragment and updates the page content appropriately, fetching data from the server via ajax requests as required. To read the fragment in js:

var fragment = location.hash;

but note that this value will include the "#" character at the beginning. To set the fragment:

location.hash = "your_state_data";

How do you make an array of structs in C?

I think you could write it that way too. I am also a student so I understand your struggle. A bit late response but ok .

#define n 3

struct {
    double p[3];//position
    double v[3];//velocity
    double a[3];//acceleration
    double radius;
    double mass;

is there any alternative for ng-disabled in angular2?

To set the disabled property to true or false use

<button [disabled]="!nextLibAvailable" (click)="showNext('library')" class=" btn btn-info btn-xs" title="Next Lib"> {{}}">
    <i class="fa fa-chevron-right fa-fw"></i>

Why is 22 the default port number for SFTP?

Why is 21 the default port for FTP? Or 80 the default for HTTP? It is a convention.

Reverse a string without using reversed() or [::-1]?

__author__ = 'Sreedhar'
#find reverse of the string with out using index or reverse function?

def reverse(text):
    revs = ""
    for i in text:
        revs = i + revs
    return revs

strig = raw_input("enter anything:")

print reverse(strig)

#index method
print strig[::-1]

Could not open a connection to your authentication agent

In my case, my Comodo firewall had sandboxed the ssh agent. Once I disabled sandboxing I was able to clone the repository.

FYI, I am using Comodo firewall on Windows 7.

Python re.sub replace with matched content

For the replacement portion, Python uses \1 the way sed and vi do, not $1 the way Perl, Java, and Javascript (amongst others) do. Furthermore, because \1 interpolates in regular strings as the character U+0001, you need to use a raw string or \escape it.

Python 3.2 (r32:88445, Jul 27 2011, 13:41:33) 
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> method = 'images/:id/huge'
>>> import re
>>> re.sub(':([a-z]+)', r'<span>\1</span>', method)

Python unicode equal comparison failed

You may use the == operator to compare unicode objects for equality.

>>> s1 = u'Hello'
>>> s2 = unicode("Hello")
>>> type(s1), type(s2)
(<type 'unicode'>, <type 'unicode'>)
>>> s1==s2
>>> s3='Hello'.decode('utf-8')
>>> type(s3)
<type 'unicode'>
>>> s1==s3

But, your error message indicates that you aren't comparing unicode objects. You are probably comparing a unicode object to a str object, like so:

>>> u'Hello' == 'Hello'
>>> u'Hello' == '\x81\x01'
__main__:1: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal

See how I have attempted to compare a unicode object against a string which does not represent a valid UTF8 encoding.

Your program, I suppose, is comparing unicode objects with str objects, and the contents of a str object is not a valid UTF8 encoding. This seems likely the result of you (the programmer) not knowing which variable holds unicide, which variable holds UTF8 and which variable holds the bytes read in from a file.

I recommend, especially the advice to create a "Unicode Sandwich."

Can we have functions inside functions in C++?


What are you trying to do?


int main(void)
  struct foo
    void operator()() { int a = 1; }

  foo b;
  b(); // call the operator()


Appropriate datatype for holding percent values?

I agree with Thomas and I would choose the DECIMAL(5,4) solution at least for WPF applications.

Have a look to the MSDN Numeric Format String to know why :

The percent ("P") format specifier multiplies a number by 100 and converts it to a string that represents a percentage.

Then you would be able to use this in your XAML code:


integrating barcode scanner into php application?

If you have Bluetooth, Use twedge on windows and getblue app on android, they also have a few videos of it. It's made by TEC-IT. I've got it to work by setting the interface option to bluetooth server in TWedge and setting the output setting in getblue to Bluetooth client and selecting my computer from the Bluetooth devices list. Make sure your computer and phone is paired. Also to get the barcode as input set the action setting in TWedge to Keyboard Wedge. This will allow for you to first click the input text box on said form, then scan said product with your phone and wait a sec for the barcode number to be put into the text box. Using this method requires no php that doesn't already exist in your current form processing, just process the text box as usual and viola your phone scans bar codes, sends them to your pc via Bluetooth wirelessly, your computer inserts the barcode into whatever text field is selected in any application or website. Hope this helps.

How to search a Git repository by commit message?

first to list the commits use

git log --oneline

then find the SHA of the commit (Message), then I used

 git log --stat 8zad24d

(8zad24d) is the SHA assosiated with the commit you are intrested in (the first couples sha example (8zad24d) you can select 4 char or 6 or 8 or the entire sha) to find the right info

Delete terminal history in Linux

You can clear your bash history like this:

history -cw

Oracle SQL - REGEXP_LIKE contains characters other than a-z or A-Z

if you want that not contains any of a-z and A-Z:

SELECT * FROM mytable WHERE NOT REGEXP_LIKE(column_1, '[A-Za-z]')

something like:

"98763045098" or "!%436%$7%$*#"

or other languages like persian, arabic and ... like this:

"???? ????"

How can I get the URL of the current tab from a Google Chrome extension?

This Solution is already TESTED.

set permissions for API in manifest.json

"permissions": [ ...

On first load call function.

chrome.tabs.onActivated.addListener((activeInfo) => {  

On change call function.

chrome.tabs.onSelectionChanged.addListener(() => {

the function to get the URL

function sendCurrentUrl() {
  chrome.tabs.getSelected(null, function(tab) {
    var tablink = tab.url

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

To resolve this for my situation:

I had to specify a more specific sub-package to install.


go get


go get

Compile to a stand-alone executable (.exe) in Visual Studio

I don't think it is possible to do what the questioner asks which is to avoid dll hell by merging all the project files into one .exe.

The framework issue is a red herring. The problem that occurs is that when you have multiple projects depending on one library it is a PITA to keep the libraries in sync. Each time the library changes, all the .exes that depend on it and are not updated will die horribly.

Telling people to learn C as one response did is arrogant and ignorant.

In Oracle SQL: How do you insert the current date + time into a table?

You may try with below query :

INSERT INTO errortable (dateupdated,table1id)
VALUES (to_date(to_char(sysdate,'dd/mon/yyyy hh24:mi:ss'), 'dd/mm/yyyy hh24:mi:ss' ),1083 );

To view the result of it:

SELECT to_char(hire_dateupdated, 'dd/mm/yyyy hh24:mi:ss') 
FROM errortable 
    WHERE table1id = 1083;

Reading a text file with SQL Server

Just discovered this:


It'll pull in the contents of the file as varchar(max). Replace SINGLE_CLOB with:

SINGLE_NCLOB for nvarchar(max) SINGLE_BLOB for varbinary(max)

Thanks to for this!

Updating GUI (WPF) using a different thread

Use Following Method to Update GUI.

     Public Void UpdateUI()
         //Here update your label, button or any string related object.

         //Dispatcher.CurrentDispatcher.Invoke(DispatcherPriority.Background, new ThreadStart(delegate { }));    
         Application.Current.Dispatcher.Invoke(DispatcherPriority.Background, new ThreadStart(delegate { }));

Keep it in Mind when you use this method at that time do not Update same object direct from dispatcher thread otherwise you get only that updated string and this method is helpless/useless. If still not working then Comment that line inside method and un-comment commented one both have nearly same effect just different way to access it.

Find a value anywhere in a database

Thanks for the really useful script.

You may need to add the following modification to the code if your tables have non-convertable fields:

SET @ColumnName =
        WHERE       TABLE_SCHEMA    = PARSENAME(@TableName, 2)
            AND TABLE_NAME  = PARSENAME(@TableName, 1)
            AND DATA_TYPE NOT IN ('text', 'image', 'ntext')                 
            AND QUOTENAME(COLUMN_NAME) > @ColumnName


Cannot find module '@angular/compiler'

In my case this was required:
npm install @angular/compiler --save
npm install @angular/cli --save-dev

"Input string was not in a correct format."

The error means that the string you're trying to parse an integer from doesn't actually contain a valid integer.

It's extremely unlikely that the text boxes will contain a valid integer immediately when the form is created - which is where you're getting the integer values. It would make much more sense to update a and b in the button click events (in the same way that you are in the constructor). Also, check out the Int.TryParse method - it's much easier to use if the string might not actually contain an integer - it doesn't throw an exception so it's easier to recover from.

How to style SVG <g> element?

You actually cannot draw Container Elements

But you can use a "foreignObject" with a "SVG" inside it to simulate what you need.

<svg width="640" height="480" xmlns="">
      <foreignObject id="G" width="300" height="200">
          <rect fill="blue" stroke-width="2" height="112" width="84" y="55" x="55" stroke-linecap="null" stroke-linejoin="null" stroke-dasharray="null" stroke="#000000"/>
          <ellipse fill="#FF0000" stroke="#000000" stroke-width="5" stroke-dasharray="null" stroke-linejoin="null" stroke-linecap="null" cx="155" cy="65" id="svg_7" rx="64" ry="56"/>     
              #G {
                background: #cff; border: 1px dashed black;
              #G:hover {
                background: #acc; border: 1px solid black;

Array Length in Java

Java arrays are actually fixed in size, and the other answers explain how .length isn't really doing what you'd expect. I'd just like to add that given your question what you might want to be using is an ArrayList, that is an array that can grow and shrink:

Here the .size() method will show you the number of elements in your list, and you can grow this as you add things.

Embed image in a <button> element

You could use input type image.

<input type="image" src="" />

It works as a button and can have the event handlers attached to it.

Alternatively, you can use css to style your button with a background image, and set the borders, margins and the like appropriately.

<button style="background: url(myimage.png)" ... />

Java - JPA - @Version annotation

Every time an entity is updated in the database the version field will be increased by one. Every operation that updates the entity in the database will have appended WHERE version = VERSION_THAT_WAS_LOADED_FROM_DATABASE to its query.

In checking affected rows of your operation the jpa framework can make sure there was no concurrent modification between loading and persisting your entity because the query would not find your entity in the database when it's version number has been increased between load and persist.

twitter-bootstrap: how to get rid of underlined button text when hovering over a btn-group within an <a>-tag?

Easy way to remove the underline from the anchor tag if you use bootstrap. for my case, I used to like this;

 <a href="#first1" class=" nav-link">
   <button type="button" class="btn btn-warning btn-lg btn-block">
   Reserve Table

Git merge is not possible because I have unmerged files

It might be the Unmerged paths that cause

error: Merging is not possible because you have unmerged files.

If so, try:

git status

if it says

You have unmerged paths.

do as suggested: either resolve conflicts and then commit or abort the merge entirely with

git merge --abort

You might also see files listed under Unmerged paths, which you can resolve by doing

git rm <file>

View the change history of a file using Git versioning

I'm probably about where the OP was when this started, looking for something simple that would let me use git difftool with vimdiff to review changes to files in my repo starting from a specific commit. I wasn't too happy with answers I was finding, so I threw this git incremental reporter (gitincrep) script together and it's been useful to me:

#!/usr/bin/env bash

shift 1

DFILES=( "$@" )

        shift 2

        if [ "$(git diff $GIT1 $GIT2 "$@")" ]
                git log ${GIT1}..${GIT2}
                git difftool --tool=vimdiff $GIT1 $GIT2 "$@"


for NEWVERS in $(git log --format=format:%h  --reverse)
        if [ "$RUNDIFF" ]
                RunDiff $OLDVERS $NEWVERS "${DFILES[@]}"
        elif [ "$OLDVERS" ]
                if [ "$NEWVERS" = "${STARTWITH:=${NEWVERS}}" ]
                        RunDiff $OLDVERS $NEWVERS "${DFILES[@]}"

Called with no args, this will start from the beginning of the repo history, otherwise it will start with whatever abbreviated commit hash you provide and proceed to the present - you can ctrl-C at any time to exit. Any args after the first will limit the difference reports to include only the files listed among those args (which I think is what the OP wanted, and I'd recommend for all but tiny projects). If you're checking changes to specific files and want to start from the beginning, you'll need to provide an empty string for arg1. If you're not a vim user, you can replace vimdiff with your favorite diff tool.

Behavior is to output the commit comments when relevant changes are found and start offering vimdiff runs for each changed file (that's git difftool behavior, but it works here).

This approach is probably pretty naive, but looking through a lot of the solutions here and at a related post, many involved installing new tools on a system where I don't have admin access, with interfaces that had their own learning curve. The above script did what I wanted without dealing with any of that. I'll look into the many excellent suggestions here when I need something more sophisticated - but I think this is directly responsive to the OP.

Can you blur the content beneath/behind a div?

you can do this with css3, this blurs the whole element

div (or whatever element) {
  -webkit-filter: blur(5px);
  -moz-filter: blur(5px);
  -o-filter: blur(5px);
  -ms-filter: blur(5px);
  filter: blur(5px);


Remove ':hover' CSS behavior from element

One method to do this is to add:

pointer-events: none;

to the element, you want to disable hover on.

(Note: this also disables javascript events on that element too, click events will actually fall through to the element behind ).

Browser Support ( 98.12% as of Jan 1, 2021 )

This seems to be much cleaner

 * This allows you to disable hover events for any elements
.disabled {
  pointer-events: none;  /* <----------- */
  opacity: 0.2;

.button {
  border-radius: 30px;
  padding: 10px 15px;
  border: 2px solid #000;
  color: #FFF;
  background: #2D2D2D;
  text-shadow: 1px 1px 0px #000;
  cursor: pointer;
  display: inline-block;
  margin: 10px;

.button-red:hover {
  background: red;

.button-green:hover {
<div class="button button-red">I'm a red button hover over me</div>

<br />

<div class="button button-green">I'm a green button hover over me</div>

<br />

<div class="button button-red disabled">I'm a disabled red button</div>

<br />

<div class="button button-green disabled">I'm a disabled green button</div>

Adding elements to an xml file in C#

You need to create a new XAttribute instead of XElement. Try something like this:

public static void Test()
    var xdoc = XDocument.Parse(@"

          <Snippet name='abc'>

          <Snippet name='xyz'>


        new XElement("Snippet",
            new XAttribute("name", "name goes here"),
            new XElement("SnippetCode", "SnippetCode"))

This generates the output:

<?xml version="1.0" encoding="utf-8"?>
  <Snippet name="abc">
  <Snippet name="xyz">
  <Snippet name="name goes here">

What's the difference between "Layers" and "Tiers"?

I like the below description from Microsoft Application Architecture Guide 2

Layers describe the logical groupings of the functionality and components in an application; whereas tiers describe the physical distribution of the functionality and components on separate servers, computers, networks, or remote locations. Although both layers and tiers use the same set of names (presentation, business, services, and data), remember that only tiers imply a physical separation.

AWK to print field $2 first, then field $1

The awk is ok. I'm guessing the file is from a windows system and has a CR (^m ascii 0x0d) on the end of the line.

This will cause the cursor to go to the start of the line after $2.

Use dos2unix or vi with :se ff=unix to get rid of the CRs.

Change hash without reload in jQuery

You can set your hash directly to URL too.

window.location.hash = "YourHash";

The result : http://url#YourHash

What does "Failure [INSTALL_FAILED_OLDER_SDK]" mean in Android Studio?

Just removing uses-sdk tag works for me for such problems.

Multi-dimensional associative arrays in JavaScript

You don't need to necessarily use Objects, you can do it with normal multi-dimensional Arrays.

This is my solution without Objects:

// Javascript
const matrix = [];

matrix.key1 = [

matrix.key2 = [

which in PHP is equivalent to:

// PHP
$matrix = [
    "key1" => [
    "key2" => [

How to convert float to int with Java

As to me, easier: (int) (a +.5) // a is a Float. Return rounded value.

Not dependent on Java Math.round() types

log4j:WARN No appenders could be found for logger in web.xml

Add log4jExposeWebAppRoot -> false in your web.xml. It works with me :)


How do you calculate program run time in python?

You might want to take a look at the timeit module:

or the profile module:

There are some additionally some nice tutorials here:

And the time module also might come in handy, although I prefer the later two recommendations for benchmarking and profiling code performance:

How to stop Python closing immediately when executed in Microsoft Windows

Well I got similar issue, It is solved by adding Environment Variable.

Add System Variables in Window


Value : C:\Python27;

Your Python path.

Edit line thickness of CSS 'underline' attribute

Recently I had to deal with FF which underlines were too thick and too far from the text in FF, and found a better way to deal with it using a pair of box-shadows:

    box-shadow: inset 0 0px 0 white, inset 0 -1px 0 black

First shadow is put on top of the second one and that's how you can control the second one by varying the 'px' value of both.

Plus: various colors, thickness and underline position

Minus: can not use on non-solid backgrounds

Here I made couple of examples:

<strong> vs. font-weight:bold & <em> vs. font-style:italic

<strong> and <em> - unlike <b> and <i> - have clear purpose for web browsers for the blind.

A blind person doesn't browse the web visually, but by sound such as text readers. <strong> and <em>, in addition to encouraging something to be bold or italic, also convey loudness or stressing syllables respectively (OH MY! & Ooooooh Myyyyyyy!). Audio-only browsers are unpredictable when it comes to <b> and <i>... they may make them loud or stress them or they may not... you never can be sure unless you use <strong> and <em>.

Excel Reference To Current Cell

=ADDRESS(ROW(),COLUMN(),4) will give us the relative address of the current cell. =INDIRECT(ADDRESS(ROW(),COLUMN()-1,4)) will give us the contents of the cell left of the current cell =INDIRECT(ADDRESS(ROW()-1,COLUMN(),4)) will give us the contents of the cell above the current cell (great for calculating running totals)

Using CELL() function returns information about the last cell that was changed. So, if we enter a new row or column the CELL() reference will be affected and will not be the current cell's any longer.

Variable number of arguments in C++?

It is possible now...using boost any and templates In this case, arguments type can be mixed

#include <boost/any.hpp>
#include <iostream>

#include <vector>
using boost::any_cast;

template <typename T, typename... Types> 
void Alert(T var1,Types... var2) 

    std::vector<boost::any> a(  {var1,var2...});

    for (int i = 0; i < a.size();i++)

    if (a[i].type() == typeid(int))
        std::cout << "int "  << boost::any_cast<int> (a[i]) << std::endl;
    if (a[i].type() == typeid(double))
        std::cout << "double "  << boost::any_cast<double> (a[i]) << std::endl;
    if (a[i].type() == typeid(const char*))
        std::cout << "char* " << boost::any_cast<const char*> (a[i]) <<std::endl;
    // etc


void main()

Entity Framework Query for inner join

from s in db.Services
join sa in db.ServiceAssignments on s.Id equals sa.ServiceId
where sa.LocationId == 1
select s

Where db is your DbContext. Generated query will look like (sample for EF6):

SELECT [Extent1].[Id] AS [Id]
       -- other fields from Services table
FROM [dbo].[Services] AS [Extent1]
INNER JOIN [dbo].[ServiceAssignments] AS [Extent2]
    ON [Extent1].[Id] = [Extent2].[ServiceId]
WHERE [Extent2].[LocationId] = 1

How to redirect to another page using PHP

Although not secure, (no offense or anything), just stick the header function after you set the session variable

 while($row = mysql_fetch_assoc($result))
            $_SESSION["user"] = $username;
header('Location: /profile.php');

How can I see all the "special" characters permissible in a varchar or char field in SQL Server?

i think that special characters are # and @ only... query will list both.

SET @str = '[azAB09ram#reddy@wer45' + CHAR(5) + 'a~b$' 
FROM   MASTER..spt_values S 
       CROSS APPLY (SELECT SUBSTRING(@str,NUMBER,1) AS poschar) t 
       AND NUMBER <= LEN(@str) 
       AND NOT (ASCII(t.poschar) BETWEEN 65 AND 90 
                 OR ASCII(t.poschar) BETWEEN 97 AND 122 
                 OR ASCII(t.poschar) BETWEEN 48 AND 57) 

Activating Anaconda Environment in VsCode

I found a hacky solution replace your environment variable for the original python file so instead it can just call from the python.exe from your anaconda folder, so when you reference python it will reference anaconda's python.

So your only python path in env var should be like:

"C:\Anaconda3\envs\py34\", or wherever the python executable lives

If you need more details I don't mind explaining. :)

SQL Server String Concatenation with Null

In Sql Server:

insert into Table_Name(PersonName,PersonEmail) values(NULL,'[email protected]')

PersonName is varchar(50), NULL is not a string, because we are not passing with in single codes, so it treat as NULL.

Code Behind:

string name = (txtName.Text=="")? NULL : "'"+ txtName.Text +"'";
string email = txtEmail.Text;

insert into Table_Name(PersonName,PersonEmail) values(name,'"+email+"')

Assigning a variable NaN in python without numpy

A more consistent (and less opaque) way to generate inf and -inf is to again use float():

>> positive_inf = float('inf')
>> positive_inf
>> negative_inf = float('-inf')
>> negative_inf

Note that the size of a float varies depending on the architecture, so it probably best to avoid using magic numbers like 9e999, even if that is likely to work.

import sys
               max_exp=1024, max_10_exp=308,
               min=2.2250738585072014e-308, min_exp=-1021,
               min_10_exp=-307, dig=15, mant_dig=53,
               epsilon=2.220446049250313e-16, radix=2, rounds=1)

How do you run a .bat file from PHP?

You might need to run it via cmd, eg:

system("cmd /c C:[path to file]");

CSS table column autowidth

The following will solve your problem:

td.last {
    width: 1px;
    white-space: nowrap;

Flexible, Class-Based Solution

And a more flexible solution is creating a .fitwidth class and applying that to any columns you want to ensure their contents are fit on one line:

td.fitwidth {
    width: 1px;
    white-space: nowrap;

And then in your HTML:

    <td class="fitwidth">ID</td>
    <td class="fitwidth">Status</td>

Remove Sub String by using Python

BeautifulSoup(text, features="html.parser").text 

For the people who were seeking deep info in my answer, sorry.

I'll explain it.

Beautifulsoup is a widely use python package that helps the user (developer) to interact with HTML within python.

The above like just take all the HTML text (text) and cast it to Beautifulsoup object - that means behind the sense its parses everything up (Every HTML tag within the given text)

Once done so, we just request all the text from within the HTML object.

break statement in "if else" - java

The "break" command does not work within an "if" statement.

If you remove the "break" command from your code and then test the code, you should find that the code works exactly the same without a "break" command as with one.

"Break" is designed for use inside loops (for, while, do-while, enhanced for and switch).

Clear a terminal screen for real

None of the answers I read worked in PuTTY, so I found a comment on this article:

In the settings for your connection, under "Window->Behavior" you'll find a setting "System Menu Appears on ALT alone". Then CTRL + L, ALT, l (that's a lower case L) will scroll the screen and then clear the scrollback buffer.

(relevant to the OP because I am connecting to an Ubuntu server, but also apparently relevant no matter what your server is running.)

How to specify the download location with wget?

From the manual page:

-P prefix
           Set directory prefix to prefix.  The directory prefix is the
           directory where all other files and sub-directories will be
           saved to, i.e. the top of the retrieval tree.  The default
           is . (the current directory).

So you need to add -P /tmp/cron_test/ (short form) or --directory-prefix=/tmp/cron_test/ (long form) to your command. Also note that if the directory does not exist it will get created.

jQuery DataTables Getting selected row values

You can iterate over the row data

$('#button').click(function () {
    var ids = $.map(table.rows('.selected').data(), function (item) {
        return item[0]
    alert(table.rows('.selected').data().length + ' row(s) selected');

Demo: Fiddle

How to calculate age in T-SQL with years, months, and days

There is an easy way, based on the hours between the two days BUT with the end date truncated.

SELECT CAST(DATEDIFF(hour,Birthdate,CAST(GETDATE() as Date))/8766.0 as INT) AS Age FROM <YourTable>

This one has proven to be extremely accurate and reliable. If it weren't for the inner CAST on the GETDATE() it might flip the birthday a few hours before midnight but, with the CAST, it is dead on with the age changing over at exactly midnight.

storing user input in array

You're not actually going out after the values. You would need to gather them like this:

var title   = document.getElementById("title").value;
var name    = document.getElementById("name").value;
var tickets = document.getElementById("tickets").value;

You could put all of these in one array:

var myArray = [ title, name, tickets ];

Or many arrays:

var titleArr   = [ title ];
var nameArr    = [ name ];
var ticketsArr = [ tickets ];

Or, if the arrays already exist, you can use their .push() method to push new values onto it:

var titleArr = [];

function addTitle ( title ) {
  titleArr.push( title );
  console.log( "Titles: " + titleArr.join(", ") );

Your save button doesn't work because you refer to this.form, however you don't have a form on the page. In order for this to work you would need to have <form> tags wrapping your fields:

I've made several corrections, and placed the changes on jsbin:

The new form follows:

  <h1>Please enter data</h1>
  <input id="title" type="text" />
  <input id="name" type="text" />
  <input id="tickets" type="text" />
  <input type="button" value="Save" onclick="insert()" />
  <input type="button" value="Show data" onclick="show()" />
<div id="display"></div>

There is still some room for improvement, such as removing the onclick attributes (those bindings should be done via JavaScript, but that's beyond the scope of this question).

I've also made some changes to your JavaScript. I start by creating three empty arrays:

var titles  = [];
var names   = [];
var tickets = [];

Now that we have these, we'll need references to our input fields.

var titleInput  = document.getElementById("title");
var nameInput   = document.getElementById("name");
var ticketInput = document.getElementById("tickets");

I'm also getting a reference to our message display box.

var messageBox  = document.getElementById("display");

The insert() function uses the references to each input field to get their value. It then uses the push() method on the respective arrays to put the current value into the array.

Once it's done, it cals the clearAndShow() function which is responsible for clearing these fields (making them ready for the next round of input), and showing the combined results of the three arrays.

function insert ( ) {
 titles.push( titleInput.value );
 names.push( nameInput.value );
 tickets.push( ticketInput.value );


This function, as previously stated, starts by setting the .value property of each input to an empty string. It then clears out the .innerHTML of our message box. Lastly, it calls the join() method on all of our arrays to convert their values into a comma-separated list of values. This resulting string is then passed into the message box.

function clearAndShow () {
  titleInput.value = "";
  nameInput.value = "";
  ticketInput.value = "";

  messageBox.innerHTML = "";

  messageBox.innerHTML += "Titles: " + titles.join(", ") + "<br/>";
  messageBox.innerHTML += "Names: " + names.join(", ") + "<br/>";
  messageBox.innerHTML += "Tickets: " + tickets.join(", ");

The final result can be used online at

Replace a string in a file with nodejs

Perhaps the "replace" module ( also would work for you. It would not require you to read and then write the file.

Adapted from the documentation:

// install:

npm install replace 

// require:

var replace = require("replace");

// use:

    regex: "string to be replaced",
    replacement: "replacement string",
    paths: ['path/to/your/file'],
    recursive: true,
    silent: true,

Android Studio Gradle project "Unable to start the daemon process /initialization of VM"

Try disabling firewall.

This might be a very weird solution but I had the same problem and I'm running Android 2.3 on windows 32 bit . I deleted the current app and disabled firewall. Upon creating a new project everything worked fine.

Disable future dates after today in Jquery Ui Datepicker

Change maxDate to current date

maxDate: new Date()

It will set current date as maximum value. Validation of viewstate MAC failed

This error message is normally displayed after you have published your website to the server.

The main problem lies in the Application Pool you use for your website.

Configure your website to use the proper .NET Framework version (i.e. v4.0) under the General section of the Application Pool related to your website.

Under the Process Model, set the Identity value to Network Service.

Close the dialog box and right-click your website and select Advanced Settings... from the Manage Website option of the content menu. In the dialog box, under General section, make sure you have selected the proper name of the Application Pool to be used.

Your website should now run without any problem.

Hope this helps you overcome this error.

How to determine if Javascript array contains an object with an attribute that equals a given value?

You cannot without looking into the object really.

You probably should change your structure a little, like

vendors = {
    Magenic:   'ABC',
    Microsoft: 'DEF'

Then you can just use it like a lookup-hash.

vendors['Microsoft']; // 'DEF'
vendors['Apple']; // undefined

Display Yes and No buttons instead of OK and Cancel in Confirm box?

There is the Jquery alert plugin

$.alerts.okButton = ' Yes ';
$.alerts.cancelButton = ' No ';

What is the difference between an Instance and an Object?

I can't believe, except for one guy no one has used the code to explain this, let me give it a shot too!

// Design Class
class HumanClass {
    var name:String
    init(name:String) { = name

var humanClassObject1 = HumanClass(name: "Rehan") 

Now the left side i.e: "humanClassObject1" is the object and the right side i.e: HumanClass(name: "Rehan") is the instance of this object.

var humanClassObject2 = HumanClass(name: "Ahmad") // again object on left and it's instance on the right.

So basically, instance contains the specific values for that object and objects contains the memory location (at run-time).

Remember the famous statement "object reference not set to an instance of an object", this means that non-initialised objects don't have any instance. In some programming languages like swift the compiler will not allow you to even design a class that don't have any way to initialise all it's members (variable eg: name, age e.t.c), but in some language you are allowed to do this:

// Design Class
class HumanClass {
    var name:String // See we don't have any way to initialise name property.

And the error will only be shown at run time when you try to do something like this:

var myClass = HumanClass()
print( // will give, object reference not set to an instance of the object.

This error indicates that, the specific values (for variables\property) is the "INSTANCE" as i tried to explain this above! And the object i.e: "myClass" contains the memory location (at run-time).

Most efficient way to see if an ArrayList contains an object in Java

If the list is sorted, you can use a binary search. If not, then there is no better way.

If you're doing this a lot, it would almost certainly be worth your while to sort the list the first time. Since you can't modify the classes, you would have to use a Comparator to do the sorting and searching.

How to sort an ArrayList in Java

Use a Comparator like this:

List<Fruit> fruits= new ArrayList<Fruit>();

Fruit fruit;
for(int i = 0; i < 100; i++)
  fruit = new Fruit();

// Sorting
Collections.sort(fruits, new Comparator<Fruit>() {
        public int compare(Fruit fruit2, Fruit fruit1)

            return  fruit1.fruitName.compareTo(fruit2.fruitName);

Now your fruits list is sorted based on fruitName.

Set value of input instead of sendKeys() - Selenium WebDriver nodejs

Thanks to Andrey-Egorov and this answer, I've managed to do it in C#

IWebDriver driver = new ChromeDriver();
IJavaScriptExecutor js = (IJavaScriptExecutor)driver;
string value = (string)js.ExecuteScript("document.getElementById('elementID').setAttribute('value', 'new value for element')");

Using LIMIT within GROUP BY to get N results per group?

Took some working, but I thougth my solution would be something to share as it is seems elegant as well as quite fast.

SELECT h.year,, h.rate 
  FROM (
    SELECT id, 
      SUBSTRING_INDEX(GROUP_CONCAT(CONCAT(id, '-', year) ORDER BY rate DESC), ',' , 5) AS l
      FROM h
      WHERE year BETWEEN 2000 AND 2009
      GROUP BY id
      ORDER BY id
  ) AS h_temp
    LEFT JOIN h ON = 
      AND SUBSTRING_INDEX(h_temp.l, CONCAT(, '-', h.year), 1) != h_temp.l

Note that this example is specified for the purpose of the question and can be modified quite easily for other similar purposes.

Get all photos from Instagram which have a specific hashtag with PHP

Here's another example I wrote a while ago:

    // Get class for Instagram
    // More examples here:
    require_once 'instagram.class.php';

    // Initialize class with client_id
    // Register at and replace client_id with your own
    $instagram = new Instagram('CLIENT_ID_HERE');

    // Set keyword for #hashtag
    $tag = 'KEYWORD HERE';

    // Get latest photos according to #hashtag keyword
    $media = $instagram->getTagMedia($tag);

    // Set number of photos to show
    $limit = 5;

    // Set height and width for photos
    $size = '100';

    // Show results
    // Using for loop will cause error if there are less photos than the limit
    foreach(array_slice($media->data, 0, $limit) as $data)
        // Show photo
        echo '<p><img src="'.$data->images->thumbnail->url.'" height="'.$size.'" width="'.$size.'" alt="SOME TEXT HERE"></p>';

how to remove untracked files in Git?

While git clean works well, I still find it useful to use my own script to clean the git repo, it has some advantages.

This shows a list of files to be cleaned, then interactively prompts to clean or not. This is nearly always what I want since interactively prompting per file gets tedious.

It also allows manual filtering of the list which comes in handy when there are file types you don't want to clean (and have reason not to commit).

readarray -t -d '' FILES < <(
    git ls-files -z --other --directory |
        grep --null-data --null -v '.bin$\|Cargo.lock$'
if [ "$FILES" = "" ]; then
    echo  "Nothing to clean!"
    exit 0

echo "Dirty files:"
printf '  %s\n' "${FILES[@]}"

while true; do
    echo ""
    read -p "Remove ${#FILES[@]} files? [y/n]: " choice
    case "$choice" in
        y|Y )
            break ;;
        n|N )
            echo "Exiting!"
            break ;;
        * ) echo "Invalid input, expected [Y/y/N/n]"
            continue ;;

if [ "$DO_REMOVE" -eq 1 ];then
    echo "Removing!"
    for f in "${FILES[@]}"; do
       rm -rfv "$f"

How to call a PHP function on the click of a button

You should make the button call the same page and in a PHP section check if the button was pressed:


<form action="theSamePage.php" method="post">
    <input type="submit" name="someAction" value="GO" />


    if($_SERVER['REQUEST_METHOD'] == "POST" and isset($_POST['someAction']))
    function func()
        // do stuff     

Add the loading screen in starting of the android application

public class Splash extends Activity {

    private final int SPLASH_DISPLAY_LENGHT = 3000;            //set your time here......

    protected void onCreate(Bundle savedInstanceState) {

        new Handler().postDelayed(new Runnable(){
            public void run() {
                /* Create an Intent that will start the Menu-Activity. */
                Intent mainIntent = new Intent(Splash.this,MainActivity.class);

How are POST and GET variables handled in Python?

suppose you're posting a html form with this:

<input type="text" name="username">

If using raw cgi:

import cgi
form = cgi.FieldStorage()
print form["username"]

If using Django, Pylons, Flask or Pyramid:

print request.GET['username'] # for GET form method
print request.POST['username'] # for POST form method

Using Turbogears, Cherrypy:

from cherrypy import request
print request.params['username']

form = web.input()
print form.username


print request.form['username']

If using Cherrypy or Turbogears, you can also define your handler function taking a parameter directly:

def index(self, username):
    print username

Google App Engine:

class SomeHandler(webapp2.RequestHandler):
    def post(self):
        name = self.request.get('username') # this will get the value from the field named username
        self.response.write(name) # this will write on the document

So you really will have to choose one of those frameworks.

An unhandled exception occurred during the execution of the current web request. ASP.NET

I had the same problem and found out that I had forgotten to include the script in the file which I want to include in the live site.

Also, you should try this:

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

CSS display:table-row does not expand when width is set to 100%

Note that according to the CSS3 spec, you do NOT have to wrap your layout in a table-style element. The browser will infer the existence of containing elements if they do not exist.

Print number of keys in Redis

After Redis 2.6, the result of INFO command are splitted by sections. In the "keyspace" section, there are "keys" and "expired keys" fields to tell how many keys are there.

Is there a MySQL option/feature to track history of changes to records?

Just my 2 cents. I would create a solution which records exactly what changed, very similar to transient's solution.

My ChangesTable would simple be:

DateTime | WhoChanged | TableName | Action | ID |FieldName | OldValue

1) When an entire row is changed in the main table, lots of entries will go into this table, BUT that is very unlikely, so not a big problem (people are usually only changing one thing) 2) OldVaue (and NewValue if you want) have to be some sort of epic "anytype" since it could be any data, there might be a way to do this with RAW types or just using JSON strings to convert in and out.

Minimum data usage, stores everything you need and can be used for all tables at once. I'm researching this myself right now, but this might end up being the way I go.

For Create and Delete, just the row ID, no fields needed. On delete a flag on the main table (active?) would be good.

Open application after clicking on Notification

Thanks to above posts, here's the main lines - distilled from the longer code answers - that are necessary to connect a notification with click listener set to open some app Activity.

private Notification getNotification(String messageText) {

    Notification.Builder builder = new Notification.Builder(this);
    // ...

    Intent appActivityIntent = new Intent(this, SomeAppActivity.class);

    PendingIntent contentAppActivityIntent =
                            this,  // calling from Activity



How do I create a custom Error in JavaScript?

If anyone is curious on how to create a custom error and get the stack trace:

function CustomError(message) { = 'CustomError';
  this.message = message || '';
  var error = new Error(this.message); =;
  this.stack = error.stack;
CustomError.prototype = Object.create(Error.prototype);

try {
  throw new CustomError('foobar');
catch (e) {
  console.log('message:', e.message);
  console.log('stack:', e.stack);

How to export data to an excel file using PHPExcel

If you've copied this directly, then:

->setCellValue('B2', Ackermann') 

should be

->setCellValue('B2', 'Ackermann') 

In answer to your question:

Get the data that you want from limesurvey, and use setCellValue() to store those data values in the cells where you want to store it.

The Quadratic.php example file in /Tests might help as a starting point: it takes data from an input form and sets it to cells in an Excel workbook.


An extremely simplistic example:

// Create your database query
$query = "SELECT * FROM myDataTable";  

// Execute the database query
$result = mysql_query($query) or die(mysql_error());

// Instantiate a new PHPExcel object
$objPHPExcel = new PHPExcel(); 
// Set the active Excel worksheet to sheet 0
// Initialise the Excel row number
$rowCount = 1; 
// Iterate through each result from the SQL query in turn
// We fetch each database result row into $row in turn
while($row = mysql_fetch_array($result)){ 
    // Set cell An to the "name" column from the database (assuming you have a column called name)
    //    where n is the Excel row number (ie cell A1 in the first row)
    $objPHPExcel->getActiveSheet()->SetCellValue('A'.$rowCount, $row['name']); 
    // Set cell Bn to the "age" column from the database (assuming you have a column called age)
    //    where n is the Excel row number (ie cell A1 in the first row)
    $objPHPExcel->getActiveSheet()->SetCellValue('B'.$rowCount, $row['age']); 
    // Increment the Excel row counter

// Instantiate a Writer to create an OfficeOpenXML Excel .xlsx file
$objWriter = new PHPExcel_Writer_Excel2007($objPHPExcel); 
// Write the Excel file to filename some_excel_file.xlsx in the current directory


Using your existing code as the basis

// Instantiate a new PHPExcel object 
$objPHPExcel = new PHPExcel();  
// Set the active Excel worksheet to sheet 0 
// Initialise the Excel row number 
$rowCount = 1;  

//start of printing column names as names of MySQL fields  
$column = 'A';
for ($i = 1; $i < mysql_num_fields($result); $i++)  
    $objPHPExcel->getActiveSheet()->setCellValue($column.$rowCount, mysql_field_name($result,$i));
//end of adding column names  

//start while loop to get data  
$rowCount = 2;  
while($row = mysql_fetch_row($result))  
    $column = 'A';
    for($j=1; $j<mysql_num_fields($result);$j++)  
            $value = NULL;  
        elseif ($row[$j] != "")  
            $value = strip_tags($row[$j]);  
            $value = "";  

        $objPHPExcel->getActiveSheet()->setCellValue($column.$rowCount, $value);

// Redirect output to a client’s web browser (Excel5) 
header('Content-Type: application/'); 
header('Content-Disposition: attachment;filename="Limesurvey_Results.xls"'); 
header('Cache-Control: max-age=0'); 
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5'); 

making a paragraph in html contain a text from a file

You'll want to use either JavaScript or a server-side language like PHP, ASP...etc

(supposedly can be done with HTML <embed> tag, which makes sense, but I haven't used, since PHP...etc is so simple/common)

Javascript can work: Here's a link to someone doing something similar via javascript on stackoverflow: How do I load the contents of a text file into a javascript variable?

PHP (as example of server-side language) is the easiest way to go though:

<div><p><?php include('myFile.txt'); ?></p></div>

To use this (if you're unfamiliar with PHP), you can:

1) check if you have php on your server

2) change the file extension of your .html file to .php

3) paste the code from my PHP example somewhere in the body of your newly-renamed PHP file

iPhone viewWillAppear not firing

A very common mistake is as follows. You have one view, UIView* a, and another one, UIView* b. You add b to a as a subview. If you try to call viewWillAppear in b, it will never be fired, because it is a subview of a

Matching strings with wildcard

Often, wild cards operate with two type of jokers:

  ? - any character  (one and only one)
  * - any characters (zero or more)

so you can easily convert these rules into appropriate regular expression:

  // If you want to implement both "*" and "?"
  private static String WildCardToRegular(String value) {
    return "^" + Regex.Escape(value).Replace("\\?", ".").Replace("\\*", ".*") + "$"; 

  // If you want to implement "*" only
  private static String WildCardToRegular(String value) {
    return "^" + Regex.Escape(value).Replace("\\*", ".*") + "$"; 

And then you can use Regex as usual:

  String test = "Some Data X";

  Boolean endsWithEx = Regex.IsMatch(test, WildCardToRegular("*X"));
  Boolean startsWithS = Regex.IsMatch(test, WildCardToRegular("S*"));
  Boolean containsD = Regex.IsMatch(test, WildCardToRegular("*D*"));

  // Starts with S, ends with X, contains "me" and "a" (in that order) 
  Boolean complex = Regex.IsMatch(test, WildCardToRegular("S*me*a*X"));

jQuery remove all list items from an unordered list

As noted by others, $('ul').empty() works fine, as does:

$('ul li').remove();

JS Fiddle demo.

Finding the number of days between two dates

You can try the code below:

$dt1 = strtotime("2019-12-12"); //Enter your first date
$dt2 = strtotime("12-12-2020"); //Enter your second date
echo abs(($dt1 - $dt2) / (60 * 60 * 24));

Retrieving the text of the selected <option> in <select> element

Easy, simple way:

const select = document.getElementById('selectID');
const selectedOption = [].find(option => option.selected).text;

How do I show the schema of a table in a MySQL database?

You can also use shorthand for describe as desc for table description.

desc [db_name.]table_name;


use db_name;
desc table_name;

You can also use explain for table description.

explain [db_name.]table_name;

See official doc

Will give output like:

| Field    | Type        | Null | Key | Default | Extra |
| id       | int(10)     | NO   | PRI | NULL    |       |
| name     | varchar(20) | YES  |     | NULL    |       |
| age      | int(10)     | YES  |     | NULL    |       |
| sex      | varchar(10) | YES  |     | NULL    |       |
| sal      | int(10)     | YES  |     | NULL    |       |
| location | varchar(20) | YES  |     | Pune    |       |

GET parameters in the URL with CodeIgniter

GET parameters are cached by the web browser, POST is not. So with a POST you don't have to worry about caching, so that is why it is usually prefered.

Equivalent of SQL ISNULL in LINQ?

Since aa is the set/object that might be null, can you check aa == null ?

(aa / xx might be interchangeable (a typo in the question); the original question talks about xx but only defines aa)


select new {
    AssetID = x.AssetID,
    Status = aa == null ? (bool?)null : aa.Online; // a Nullable<bool>

or if you want the default to be false (not null):

select new {
    AssetID = x.AssetID,
    Status = aa == null ? false : aa.Online;

Update; in response to the downvote, I've investigated more... the fact is, this is the right approach! Here's an example on Northwind:

        using(var ctx = new DataClasses1DataContext())
            ctx.Log = Console.Out;
            var qry = from boss in ctx.Employees
                      join grunt in ctx.Employees
                          on boss.EmployeeID equals grunt.ReportsTo into tree
                      from tmp in tree.DefaultIfEmpty()
                      select new
                                 ID = boss.EmployeeID,
                                 Name = tmp == null ? "" : tmp.FirstName
            foreach(var row in qry)
                Console.WriteLine("{0}: {1}", row.ID, row.Name);

And here's the TSQL - pretty much what we want (it isn't ISNULL, but it is close enough):

SELECT [t0].[EmployeeID] AS [ID],
        WHEN [t2].[test] IS NULL THEN CONVERT(NVarChar(10),@p0)
        ELSE [t2].[FirstName]
     END) AS [Name]
FROM [dbo].[Employees] AS [t0]
    SELECT 1 AS [test], [t1].[FirstName], [t1].[ReportsTo]
    FROM [dbo].[Employees] AS [t1]
    ) AS [t2] ON ([t0].[EmployeeID]) = [t2].[ReportsTo]
-- @p0: Input NVarChar (Size = 0; Prec = 0; Scale = 0) []
-- Context: SqlProvider(Sql2008) Model: AttributedMetaModel Build: 3.5.30729.1


How do I SET the GOPATH environment variable on Ubuntu? What file must I edit?

This has been the most annoying thing to deal with. In hopes of saving your time.

IF go was installed as root user. The root user of your system's bash_profile text file ~/.bash_profile needs to have $GOROOT assigned to the go install directory and $GOPATH needs to be assigned to go /src directory.

  ...$# sudo su
  ...$# vi ~/.bash_profile

    ***Story continues in vi editor***

    [your regular PATH stuff here]

be sure the path to go binary is in your path on .bash_profile


This PATH can be as long a string it needs to add new items just separate by colon :

exit vi editor and saving bash profile (:wq stands for write and quit)

  [shift] + [:] 

You have to log out of terminal and log back in for profile to initiate again..or you can just kick start it by using export.

...$# export GOPATH=/usr/local/go/src

You can verify go env:

...$# go env



Now you can sudo and go will be able to download and create directories inside go/src and you can get down to what you were trying to get done.


# sudo go get

Now you will run into another might not have git installed..that's another adventure..:)

Amazon AWS Filezilla transfer permission denied

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

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

Make sure permissions on that entire folder were correct:

chmod -R 755 /var/www/html


Setting up amazon ec2-instances

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

Understanding and Using File Permissions

What Regex would capture everything from ' mark to the end of a line?

In your example I'd go for the following pattern:


use multiline and global options to match all occurences.

To include the linefeed in the match you could use:


But this might miss the last line if it has no linefeed.

For a single line, if you don't need to match the linefeed I'd prefer to use:


git push >> fatal: no configured push destination

You are referring to the section "2.3.5 Deploying the demo app" of this "Ruby on Rails Tutorial ":

In section 2.3.1 Planning the application, note that they did:

$ git remote add origin [email protected]:<username>/demo_app.git
$ git push origin master

That is why a simple git push worked (using here an ssh address).
Did you follow that step and made that first push?

wouldn't be a writable URI for pushing to a GitHub repo.

https://[email protected]/levelone/demo_app.git

should be more appropriate.
Check what git remote -v returns, and if you need to replace the remote address, as described in GitHub help page, use git remote --set-url.

git remote set-url origin https://[email protected]/levelone/demo_app.git
git remote set-url origin [email protected]:levelone/demo_app.git

ios simulator: how to close an app

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

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

Access to the path denied error in C#

You are trying to create a FileStream object for a directory (folder). Specify a file name (e.g. @"D:\test.txt") and the error will go away.

By the way, I would suggest that you use the StreamWriter constructor that takes an Encoding as its second parameter, because otherwise you might be in for an unpleasant surprise when trying to read the saved file later (using StreamReader).

SELECT data from another schema in oracle

Does the user that you are using to connect to the database (user A in this example) have SELECT access on the objects in the PCT schema? Assuming that A does not have this access, you would get the "table or view does not exist" error.

Most likely, you need your DBA to grant user A access to whatever tables in the PCT schema that you need. Something like

GRANT SELECT ON pct.pi_int
   TO a;

Once that is done, you should be able to refer to the objects in the PCT schema using the syntax pct.pi_int as you demonstrated initially in your question. The bracket syntax approach will not work.

Read a text file line by line in Qt

Use this code:

QFile inputFile(fileName);
if (
   QTextStream in(&inputFile);
   while (!in.atEnd())
      QString line = in.readLine();

String comparison in bash. [[: not found

I had this problem when installing Heroku Toolbelt

This is how I solved the problem

$ ls -l /bin/sh
lrwxrwxrwx 1 root root 4 ago 15  2012 /bin/sh -> dash

As you can see, /bin/sh is a link to "dash" (not bash), and [[ is bash syntactic sugarness. So I just replaced the link to /bin/bash. Careful using rm like this in your system!

$ sudo rm /bin/sh
$ sudo ln -s /bin/bash /bin/sh

C# - Making a Process.Start wait until the process has start-up

I used the EventWaitHandle class. On the parent process, create a named EventWaitHandle with initial state of the event set to non-signaled. The parent process blocks until the child process calls the Set method, changing the state of the event to signaled, as shown below.

Parent Process:

using System;
using System.Threading;
using System.Diagnostics;

namespace MyParentProcess
    class Program
        static void Main(string[] args)
            EventWaitHandle ewh = null;
                ewh = new EventWaitHandle(false, EventResetMode.AutoReset, "CHILD_PROCESS_READY");

                Process process = Process.Start("MyChildProcess.exe", Process.GetCurrentProcess().Id.ToString());
                if (process != null)
                    if (ewh.WaitOne(10000))
                        // Child process is ready.
            catch(Exception exception)
            { }
                if (ewh != null)

Child Process:

using System;
using System.Threading;
using System.Diagnostics;

namespace MyChildProcess
    class Program
        static void Main(string[] args)
                // Representing some time consuming work.


            catch (Exception exception)
            { }

Creating a file only if it doesn't exist in Node.js

Todo this in a single system call you can use the fs-extra npm module. After this the file will have been created as well as the directory it is to be placed in.

const fs = require('fs-extra');
const file = '/tmp/this/path/does/not/exist/file.txt'
fs.ensureFile(file, err => {
    console.log(err) // => null

Another way is to use ensureFileSync which will do the same thing but synchronous.

const fs = require('fs-extra');
const file = '/tmp/this/path/does/not/exist/file.txt'

System.loadLibrary(...) couldn't find native library in my case

This is an Android 8 update.

In earlier version of Android, to LoadLibrary native shared libraries (for access via JNI for example) I hard-wired my native code to iterate through a range of potential directory paths for the lib folder, based on the various apk installation/upgrade algorithms:


This approach is hokey and will not work for Android 8; from you'll see that as part of their "Security" changes you now need to use sourceDir:

"You can no longer assume that APKs reside in directories whose names end in -1 or -2. Apps should use sourceDir to get the directory, and not rely on the directory format directly."

Correction, sourceDir is not the way to find your native shared libraries; use something like. Tested for Android 4.4.4 --> 8.0

// Return Full path to the directory where native JNI libraries are stored.
private static String getNativeLibraryDir(Context context) {
    ApplicationInfo appInfo = context.getApplicationInfo();
    return appInfo.nativeLibraryDir;

Circle line-segment collision detection algorithm?

Weirdly I can answer but not comment... I liked Multitaskpro's approach of shifting everything to make the centre of the circle fall on the origin. Unfortunately there are two problems in his code. First in the under-the-square-root part you need to remove the double power. So not:

var underRadical = Math.pow((Math.pow(r,2)*(Math.pow(m,2)+1)),2)-Math.pow(b,2));


var underRadical = Math.pow(r,2)*(Math.pow(m,2)+1)) - Math.pow(b,2);

In the final coordinates he forgets to shift the solution back. So not:

var i1 = {x:t1,y:m*t1+b}


var i1 = {x:t1+c.x, y:m*t1+b+c.y};

The whole function then becomes:

function interceptOnCircle(p1, p2, c, r) {
    //p1 is the first line point
    //p2 is the second line point
    //c is the circle's center
    //r is the circle's radius

    var p3 = {x:p1.x - c.x, y:p1.y - c.y}; //shifted line points
    var p4 = {x:p2.x - c.x, y:p2.y - c.y};

    var m = (p4.y - p3.y) / (p4.x - p3.x); //slope of the line
    var b = p3.y - m * p3.x; //y-intercept of line

    var underRadical = Math.pow(r,2)*Math.pow(m,2) + Math.pow(r,2) - Math.pow(b,2); //the value under the square root sign 

    if (underRadical < 0) {
        //line completely missed
        return false;
    } else {
        var t1 = (-m*b + Math.sqrt(underRadical))/(Math.pow(m,2) + 1); //one of the intercept x's
        var t2 = (-m*b - Math.sqrt(underRadical))/(Math.pow(m,2) + 1); //other intercept's x
        var i1 = {x:t1+c.x, y:m*t1+b+c.y}; //intercept point 1
        var i2 = {x:t2+c.x, y:m*t2+b+c.y}; //intercept point 2
        return [i1, i2];

iPhone 5 CSS media query

There is this, which I credit to this blog:

@media only screen and (min-device-width: 560px) and (max-device-width: 1136px) and (-webkit-min-device-pixel-ratio: 2) {
    /* iPhone 5 only */

Keep in mind it reacts the iPhone 5, not to the particular iOS version installed on said device.

To merge with your existing version, you should be able to comma-delimit them:

@media only screen and (max-device-width: 480px), only screen and (min-device-width: 560px) and (max-device-width: 1136px) and (-webkit-min-device-pixel-ratio: 2) {
    /* iPhone only */

NB: I haven't tested the above code, but I've tested comma-delimited @media queries before, and they work just fine.

Note that the above may hit some other devices which share similar ratios, such as the Galaxy Nexus. Here is an additional method which will target only devices which have one dimension of 640px (560px due to some weird display-pixel anomalies) and one of between 960px (iPhone <5) and 1136px (iPhone 5).

    only screen and (max-device-width: 1136px) and (min-device-width: 960px) and (max-device-height: 640px) and (min-device-height: 560px),
    only screen and (max-device-height: 1136px) and (min-device-height: 960px) and (max-device-width: 640px) and (min-device-width: 560px) {
    /* iPhone only */

How do I kill a VMware virtual machine that won't die?

Here's what I did based on

a) @Espo 's comments and
b) the fact that I only had Windows Task Manager to play with....

I logged onto the host machine, opened Task Manager and used the view menu to add the PID column to the Processes tab.

I wrote down (yes, with paper and a pen) the PID's for each and every instance of the vmware-wmx.exe process that was running on the box.

Using the VMWare console, I suspended the errant virtual machine.

When I resumed it, I could then identify the vmware-vmx process that corresponded to my machine and could kill it.

There doesn't seem to have been any ill effects so far.

laravel-5 passing variable to JavaScript

$langs = Language::all()->toArray();
return View::make('NAATIMockTest.Admin.Language.index', [
    'langs' => $langs

then in view

<script type="text/javascript">
    var langs = {{json_encode($langs)}};

Its not pretty tho

Display List in a View MVC

You are passing wrong mode to you view. Your view is looking for @model IEnumerable<Standings.Models.Teams> and you are passing var model = tm.Name.ToList(); name list. You have to pass list of Teams.

You have to pass following model

var model = new List<Teams>();

model.Add(new Teams { Name =  new List<string>(){"Sky","ABC"}});
model.Add(new Teams { Name =  new List<string>(){"John","XYZ"} });
return View(model);

Java Replace Character At Specific Position Of String?

Use StringBuilder:

StringBuilder sb = new StringBuilder(str);
sb.setCharAt(i - 1, 'k');
str = sb.toString();

Prevent flicker on webkit-transition of webkit-transform

I had to use:

-webkit-perspective: 1000;
-webkit-backface-visibility: hidden;    

on the element, or I would still get a flickr the first time a transition occurred after page load

Creating the checkbox dynamically using JavaScript?

   /* worked for me  */
     <div id="divid"> </div>
     <script type="text/javascript">
         var hold = document.getElementById("divid");
         var checkbox = document.createElement('input');
         checkbox.type = "checkbox"; = "chkbox1"; = "cbid";
         var label = document.createElement('label');
         var tn = document.createTextNode("Not A RoBot");

Using the "start" command with parameters passed to the started program

None of these answers worked for me.

Instead, I had to use the Call command:

Call "\\Path To Program\Program.exe" <parameters>

I'm not sure this actually waits for completion... the C++ Redistributable I was installing went fast enough that it didn't matter

Javascript Regexp dynamic generation from variables?

Use the below:

var regEx = new RegExp(pattern1+'|'+pattern2, 'gi');


Using routes in Express-js

The route-map express example matches url paths with objects which in turn matches http verbs with functions. This lays the routing out in a tree, which is concise and easy to read. The apps's entities are also written as objects with the functions as enclosed methods.

var express = require('../../lib/express')
  , verbose = process.env.NODE_ENV != 'test'
  , app = module.exports = express(); = function(a, route){
  route = route || '';
  for (var key in a) {
    switch (typeof a[key]) {
      // { '/path': { ... }}
      case 'object':[key], route + key);
      // get: function(){ ... }
      case 'function':
        if (verbose) console.log('%s %s', key, route);
        app[key](route, a[key]);

var users = {
  list: function(req, res){
    res.send('user list');

  get: function(req, res){
    res.send('user ' + req.params.uid);

  del: function(req, res){
    res.send('delete users');

var pets = {
  list: function(req, res){
    res.send('user ' + req.params.uid + '\'s pets');

  del: function(req, res){
    res.send('delete ' + req.params.uid + '\'s pet ' +;
  '/users': {
    get: users.list,
    del: users.del,
    '/:uid': {
      get: users.get,
      '/pets': {
        get: pets.list,
        '/:pid': {
          del: pets.del


Logging POST data from $request_body

Ok. So finally I was able to log the post data and return a 200. It's kind of a hacky solution that I'm not too proud of which basically overrides the natural behavior for error_page, but my inexperience of nginx plus timelines lead me to this solution:

location /bk {
  if ($request_method != POST) {
    return 405;
  proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header Host $host;
  proxy_set_header X-Real-IP $remote_addr;
  proxy_redirect off;
  proxy_pass $scheme://$server_port/success;
  log_format my_tracking $request_body;
  access_log  /mnt/logs/nginx/my_tracking.access.log my_tracking;
location /success {
  return 200;
error_page   500 502 503 504  /50x.html;
location = /50x.html {
  root   /var/www/nginx-default;
  log_format my_tracking $request_body;
  access_log  /mnt/logs/nginx/my_tracking.access.log my_tracking_2;

Now according to that config, it would seem that the proxy pass would return a 200 all the time. Occasionally I would get 500 but when I threw in an error_log to see what was going on, all of my request_body data was in there and I couldn't see a problem. So I caught that and wrote to the same log. Since nginx doesn't like the same name for the tracking variable, I just used my_tracking_2 and wrote to the same log as when it returns a 200. Definitely not the most elegant solution and I welcome any better solution. I've seen the post module, but in my scenario, I couldn't recompile from source.

MySQL ON DUPLICATE KEY UPDATE for multiple rows insert in single query

You can use Replace instead of INSERT ... ON DUPLICATE KEY UPDATE.

Jquery Date picker Default Date

interesting, datepicker default date is current date as I found,

but you can set date by

$("#yourinput").datepicker( "setDate" , "7/11/2011" );

don't forget to check you system date :)

Can we import XML file into another XML file?

You could use an external (parsed) general entity.

You declare the entity like this:

<!ENTITY otherFile SYSTEM "otherFile.xml">

Then you reference it like this:


A complete example:

<?xml version="1.0" standalone="no" ?>
<!DOCTYPE doc [
<!ENTITY otherFile SYSTEM "otherFile.xml">

When the XML parser reads the file, it will expand the entity reference and include the referenced XML file as part of the content.

If the "otherFile.xml" contained: <baz>this is my content</baz>

Then the XML would be evaluated and "seen" by an XML parser as:

<?xml version="1.0" standalone="no" ?>
    <bar><baz>this is my content</baz></bar>

A few references that might be helpful:

Replacing .NET WebBrowser control with a better browser, like Chrome?

Chrome uses (a fork of) Webkit if you didn't know, which is also used by Safari. Here's a few questions that are of the same vein:

The webkit one isn't great as the other answer states, one version no longer works (the google code one) and the Mono one is experimental. It'd be nice if someone made the effort to make a decent .NET wrapper for it but it's not something anyone seems to want to do - which is surprising given it now has support for HTML5 and so many other features that the IE(8) engine lacks.

Update (2014)

There's new dual-licensed project that allows you embed Chrome into your .NET applications called Awesomium. It comes with a .NET api but requires quite a few hacks for rendering (the examples draw the browser window to a buffer, paint the buffer as an image and refresh on a timer).

I think this is the browser used by Origin in Battlefield 3.

Update (2016)

There is now DotnetBrowser, a commercial alternative to Awesomium. It's based off Chromium.

How to match a substring in a string, ignoring case

If you don't want to use str.lower(), you can use a regular expression:

import re

if'mandy', 'Mandy Pande', re.IGNORECASE):
    # Is True

application/x-www-form-urlencoded or multipart/form-data?

I agree with much that Manuel has said. In fact, his comments refer to this url...

... which states:

The content type "application/x-www-form-urlencoded" is inefficient for sending large quantities of binary data or text containing non-ASCII characters. The content type "multipart/form-data" should be used for submitting forms that contain files, non-ASCII data, and binary data.

However, for me it would come down to tool/framework support.

  • What tools and frameworks do you expect your API users to be building their apps with?
  • Do they have frameworks or components they can use that favour one method over the other?

If you get a clear idea of your users, and how they'll make use of your API, then that will help you decide. If you make the upload of files hard for your API users then they'll move away, of you'll spend a lot of time on supporting them.

Secondary to this would be the tool support YOU have for writing your API and how easy it is for your to accommodate one upload mechanism over the other.

Http 415 Unsupported Media type error with JSON

I was sending "delete" rest request and it failed with 415. I saw what content-type my server uses to hit the api. In my case, It was "application/json" instead of "application/json; charset=utf8".

So ask from your api developer And in the meantime try sending request with content-type= "application/json" only.

How do I install ASP.NET MVC 5 in Visual Studio 2012?

I had trouble with the web installer not "finding the product"

The stand alone installer is located here:

The release/installation notes can be found at


  • .NET 4.5
  • You need to select this version of the framework when creating a new project in order to view the MVC 5 project templates.


  • MVC5
  • Entity Framework 6
  • Web API 2
  • Bootstrap
  • Razor
  • Nuget 2.7

jquery find class and get the value

var myVar = $("#start").find('myClass').val();

needs to be

var myVar = $("#start").find('.myClass').val();

Remember the CSS selector rules require "." if selecting by class name. The absence of "." is interpreted to mean searching for <myclass></myclass>.

How to navigate through a vector using iterators? (C++)

Typically, iterators are used to access elements of a container in linear fashion; however, with "random access iterators", it is possible to access any element in the same fashion as operator[].

To access arbitrary elements in a vector vec, you can use the following:

vec.begin()                  // 1st
vec.begin()+1                // 2nd
// ...
vec.begin()+(i-1)            // ith
// ...
vec.begin()+(vec.size()-1)   // last

The following is an example of a typical access pattern (earlier versions of C++):

int sum = 0;
using Iter = std::vector<int>::const_iterator;
for (Iter it = vec.begin(); it!=vec.end(); ++it) {
    sum += *it;

The advantage of using iterator is that you can apply the same pattern with other containers:

sum = 0;
for (Iter it = lst.begin(); it!=lst.end(); ++it) {
    sum += *it;

For this reason, it is really easy to create template code that will work the same regardless of the container type. Another advantage of iterators is that it doesn't assume the data is resident in memory; for example, one could create a forward iterator that can read data from an input stream, or that simply generates data on the fly (e.g. a range or random number generator).

Another option using std::for_each and lambdas:

sum = 0;
std::for_each(vec.begin(), vec.end(), [&sum](int i) { sum += i; });

Since C++11 you can use auto to avoid specifying a very long, complicated type name of the iterator as seen before (or even more complex):

sum = 0;
for (auto it = vec.begin(); it!=vec.end(); ++it) {
    sum += *it;

And, in addition, there is a simpler for-each variant:

sum = 0;
for (auto value : vec) {
    sum += value;

And finally there is also std::accumulate where you have to be careful whether you are adding integer or floating point numbers.

Using any() and all() to check if a list contains one set of values or another

Generally speaking:

all and any are functions that take some iterable and return True, if

  • in the case of all(), no values in the iterable are falsy;
  • in the case of any(), at least one value is truthy.

A value x is falsy iff bool(x) == False. A value x is truthy iff bool(x) == True.

Any non-booleans in the iterable will be fine — bool(x) will coerce any x according to these rules: 0, 0.0, None, [], (), [], set(), and other empty collections will yield False, anything else True. The docstring for bool uses the terms 'true'/'false' for 'truthy'/'falsy', and True/False for the concrete boolean values.

In your specific code samples:

You misunderstood a little bit how these functions work. Hence, the following does something completely not what you thought:

if any(foobars) == big_foobar:

...because any(foobars) would first be evaluated to either True or False, and then that boolean value would be compared to big_foobar, which generally always gives you False (unless big_foobar coincidentally happened to be the same boolean value).

Note: the iterable can be a list, but it can also be a generator/generator expression (˜ lazily evaluated/generated list) or any other iterator.

What you want instead is:

if any(x == big_foobar for x in foobars):

which basically first constructs an iterable that yields a sequence of booleans—for each item in foobars, it compares the item to big_foobar and emits the resulting boolean into the resulting sequence:

tmp = (x == big_foobar for x in foobars)

then any walks over all items in tmp and returns True as soon as it finds the first truthy element. It's as if you did the following:

In [1]: foobars = ['big', 'small', 'medium', 'nice', 'ugly']                                        

In [2]: big_foobar = 'big'                                                                          

In [3]: any(['big' == big_foobar, 'small' == big_foobar, 'medium' == big_foobar, 'nice' == big_foobar, 'ugly' == big_foobar])        
Out[3]: True

Note: As DSM pointed out, any(x == y for x in xs) is equivalent to y in xs but the latter is more readable, quicker to write and runs faster.

Some examples:

In [1]: any(x > 5 for x in range(4))
Out[1]: False

In [2]: all(isinstance(x, int) for x in range(10))
Out[2]: True

In [3]: any(x == 'Erik' for x in ['Erik', 'John', 'Jane', 'Jim'])
Out[3]: True

In [4]: all([True, True, True, False, True])
Out[4]: False

See also:

Java - Writing strings to a CSV file

 private static final String FILE_HEADER ="meter_Number,latestDate";
    private static final String COMMA_DELIMITER = ",";
    private static final String NEW_LINE_SEPARATOR = "\n";
    static SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:m m:ss");

    private void writeToCsv(Map<String, Date> meterMap) {
        try {
            Iterator<Map.Entry<String, Date>> iter = meterMap.entrySet().iterator();
            FileWriter fw = new FileWriter("smaple.csv");
            while (iter.hasNext()) {
                Map.Entry<String, Date> entry =;
                try {
                } catch (Exception e) {
                } finally {
        } catch (Exception e) {

What is the size of column of int(11) in mysql in bytes?

according to this book:

MySQL lets you specify a “width” for integer types, such as INT(11). This is meaningless for most applications: it does not restrict the legal range of values, but simply specifies the number of characters MySQL’s interactive tools will reserve for display purposes. For storage and computational purposes, INT(1) is identical to INT(20).

INFO: No Spring WebApplicationInitializer types detected on classpath

I found the error: I have a library that it was built using jdk 1.6. The Spring main controller and components are in this library. And how I use jdk 1.7, It does not find the classes built in 1.6.

The solution was built all using "compiler compliance level: 1.7" and "Generated .class files compatibility: 1.6", "Source compatibility: 1.6".

I setup this option in Eclipse: Preferences\Java\Compiler.

Thanks everybody.

JS regex: replace all digits in string

You need to add the "global" flag to your regex:

s.replace(new RegExp("[0-9]", "g"), "X")

or, perhaps prettier, using the built-in literal regexp syntax:

.replace(/[0-9]/g, "X")

Delete first character of a string in Javascript

Did you try the substring function?

string = string.indexOf(0) == '0' ? string.substring(1) : string;

Here's a reference -

And you can always do this for multiple 0s:

while(string.indexOf(0) == '0')
    string = string.substring(1);