if(variableName == null )
{
    //do something.....
}

but this will not check if the object is empty.

Use this function to check if the object is empty.

function isObjectEmpty(object)
{
  var isEmpty = true;
  for(keys in object)
  {
     isEmpty = false;
     break; // exiting since we found that the object is not empty
  }
  return isEmpty;
}

How to use the function

var myObject = {}; // Object is empty
var isEmpty  = isObjectEmpty(myObject); // will return true;

// populating the object
myObject = {"name":"John Smith","Address":"Kochi, Kerala"}; 

// check if the object is empty
isEmpty  = isObjectEmpty(myObject); // will return false;

function add3Dots(string, limit)
{
  var dots = "...";
  if(string.length > limit)
  {
    // you can also use substr instead of substring
    string = string.substring(0,limit) + dots;
  }

    return string;
}

Call like this

add3Dots("Hello World",9);

The above function call returns this string

Hello Wor...

A minified version of the above function is given here

function add3Dots(string, limit)
{
   return string = string.length > limit ? string.substring(0,limit) + "...": string;
}

A über minified version (with the price of readability) is given here

function aD(s,l){return s=s.length>l?s.substring(0,l)+"...":s;}

In this case you need to call like this…

aD("Hello World",9);

var newObject = jQuery.extend({}, oldObject);

Deep copy

var newObject = jQuery.extend(true, {}, oldObject);

What is shallow copy and deep copy?

If you need to copy(clone) object a  to object b  in Javascript using jQuery, do like this.

// old object
var a = {"name":"John Smith", "age":"30"};

// new object, we need to copy the contents of object a to object b
var b =  jQuery.extend(true, {}, a);

This is a sample program

// old object
var a = {"name":"John Smith", "age":"30"};

console.log("Printing the contents of object a in Firebug console");
console.log(a);

// new object, we need to copy the contents of object a to object b
var b =  jQuery.extend(true, {}, a);

console.log("Printing the contents of object a in Firebug console");
console.log(b);

// Now we are editing the contents of object a
a.name = "Mary Smith";
a.age = "31"

// Print the object again
console.log("Printing the contents of object a in Firebug console");
console.log(a);
console.log("Printing the contents of object b in Firebug console");
console.log(b);

// Note that even though we changed the contents of object a, the contents of object b is not changed.

The output in firebug console will look like this.

Printing the contents of object a in Firebug console
Object { name="John Smith", age="30"}
Printing the contents of object a in Firebug console
Object { name="John Smith", age="30"}
Printing the contents of object a in Firebug console
Object { name="Mary Smith", age="31"}
Printing the contents of object b in Firebug console
Object { name="John Smith", age="30"}
Note that even though we changed the contents of object a, the contents of object b is not changed.

Hope this information is useful to you.

MovieClip(root).someThing;

For example suppose you have a text box in root with instance name txtAddress in your root. If you need to set the text of txtAddress from a movie clip the code should be like

MovieClip(root).txtAddress.text = "Some text here."

var startTime:Date = new Date();

// execute your code here

var endTime:Date = new Date();
trace("Time take to execute the code "+String(endTime.getTime()-startTime.getTime())+" milliseconds");

Check PHP version here

Check Javascript version here

Dim startTime
startTime = Now

'execute your code here

endTime = Now
MsgBox("Time taken to execute code : " & DateDiff("s",startTime,endTime)&" seconds")

You can try this example

Dim startTime
startTime = Now

'execute your code here
MsgBox("Wait for sometime")

endTime = Now
MsgBox("Time taken to execute code : " & DateDiff("s",startTime,endTime)&" seconds")

Check PHP version here

var startDate = new Date();

// execute your tasks here

var endDate = new Date();

var timeTaken = endDate.getTime() - startDate.getTime();

alert('Time take to execute the script is '+timeTaken+' milliseconds');

You can try this example

// USE OF THIS FUNCTION IS NOT RECOMMENDED, CONSUMES LOT OF SYSTEM RESOURCES
function sleep(milliSeconds){
	var startTime = new Date().getTime(); // get the current time
	while (new Date().getTime() < startTime + milliSeconds); // hog cpu
}

var startDate = new Date();

// execute your tasks here
sleep(300); // parameter is milliseconds

var endDate = new Date();
var timeTaken = endDate.getTime() - startDate.getTime();

alert('Time take to execute the script is '+timeTaken+' milliseconds');

sleep function taken from http://www.devcheater.com/#JavaScript sleep by loop. Usage of this sleep function is not recommended, shown only for demo purpose.

Check PHP version here

Type about:plugins in Google Chrome address bar and hit Enter to view all installed plugins.

From this screen you can Enable or Disable a plugin.

$time_start = microtime(true);

// execute your tasks here

$time_end = microtime(true);
$time = $time_end - $time_start;

echo "Code executed in $time seconds\n";

You can try these examples

$time_start = microtime(true);

// execute your tasks here
phpinfo();

$time_end = microtime(true);
$time = $time_end - $time_start;

echo "Code executed in $time seconds\n";

Another example

$time_start = microtime(true);

// execute your tasks here
sleep(1); // wait for 1 second

$time_end = microtime(true);
$time = $time_end - $time_start;

echo "Code executed in $time seconds\n";

ASP and C# version of the code can be found here

Check Javascript version here

Login to admin console of your website.

1. Goto Appearance->Editor
2. Click to edit Header (header.php) from the right side of page.
3. Navigate to code which looks like this

   <span>
   
   <a href="<?php echo home_url( '/' ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a>
   
   </span>
   

4. First lets comment the blog title
   Comment like this, or you can remove this line.

   <?php //bloginfo( 'name' ); ?>
   

5. Next we need to add logo or image
6. Insert image like this

   <img src="http://einternals.com/images/einternals-logo.gif" width="260" height="48" />
   

7. So the full code will look like

   <span>
   
   <a href="<?php echo home_url( '/' ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home"><img src="http://einternals.com/images/einternals-logo.gif" width="260" height="48" /><?php //bloginfo( 'name' ); ?></a>
   
   </span>
   

Now the image or company logo you added will be displayed in the blog header.