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JavaScript lastIndex Property

RegExp Object Reference JavaScript RegExp Object

Definition and Usage

The lastIndex property specifies the index at which to start the next match.

Note: This property only works if the "g" modifier is set.

This property returns an integer that specifies the character position immediately after the last match found by exec( ) or test( ) methods.

Note: exec( ) and test( ) reset lastIndex to 0 if they do not get a match.

Syntax

RegExpObject.lastIndex

Example

Example

Do a global search for "ain" in a string, and output the index after a match is found:

<script type="text/javascript">
var str="The rain in Spain stays mainly in the plain";
var patt1=/ain/g;

while (patt1.test(str)==true)
  {
  document.write("'ain' found. Index now at: "+patt1.lastIndex);
  document.write("<br />");
  }
</script>

Try it yourself »

RegExp Object Reference JavaScript RegExp Object

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