From http://www.w3schools.com (Copyright Refsnes Data)

JavaScript substr() Method

String Object Reference JavaScript String Object

Definition and Usage

The substr() method extracts a specified number of characters from a string, and returns the new string.

Syntax

stringObject.substr(start,length)

Parameter Description
start Required. Where to start the extraction. Must be a numeric value. Starts at 0
length Optional. An integer that defines how many characters to extract. If omitted, substr() extracts to the end of the string

Tips and Notes

Tip: To extract characters from the end of the string, use a negative start number (This does not work in IE).

Example

Example

Extract some characters from a string:

<script type="text/javascript">

var str="Hello world!";

document.write(str.substr(3)+"<br />");
document.write(str.substr(3,4));

</script>

The output of the code above will be:

lo world!
lo w

Try it yourself »

String Object Reference JavaScript String Object

From http://www.w3schools.com (Copyright Refsnes Data)