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

JavaScript replace() Method

String Object Reference JavaScript String Object

Definition and Usage

The replace() method finds a match between a substring (or regular expression) and a string, and replaces the matched substring with a new substring.

Syntax

stringObject.replace(regexp/substr,newstring)

Parameter Description
regexp/substr Required. A substring or a regular expression object. Read more about the RegExp object
newstring Required. The string to replace the found value in parameter 1

Examples

Example 1

Perform a case-sensitive search:

<script type="text/javascript">

var str="Visit Microsoft!";
document.write(str.replace("Microsoft", "W3Schools"));

</script>

The output of the code above will be:

Visit W3Schools!

Try it yourself »

Example 2

Perform a case-insensitive search:

<script type="text/javascript">

var str="Visit Microsoft!";
document.write(str.replace(/microsoft/i, "W3Schools"));

</script>

The output of the code above will be:

Visit W3Schools!

Try it yourself »

Example 3

Perform a global, case-insensitive search (the word Microsoft will be replaced each time it is found):

<script type="text/javascript">

var str="Welcome to Microsoft! ";
str=str + "We are proud to announce that Microsoft has ";
str=str + "one of the largest Web Developers sites in the world.";

document.write(str.replace(/microsoft/gi, "W3Schools"));

</script>

The output of the code above will be:

Welcome to W3Schools! We are proud to announce that W3Schools
has one of the largest Web Developers sites in the world.

Try it yourself »

String Object Reference JavaScript String Object

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