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Javascript String - indexOf() Method

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This method returns the index within the calling String object of the first occurrence of the specified value, starting the search at fromIndex or -1 if the value is not found.


string.indexOf(searchValue[, fromIndex])

Here is the detail of parameters:

  • searchValue : A string representing the value to search for.

  • fromIndex : The location within the calling string to start the search from. It can be any integer between 0 and the length of the string. The default value is 0.

Return Value:

Returns the index of the found occurrence otherwise -1 if not found.


<title>JavaScript String indexOf() Method</title>
<script type="text/javascript">
var str1 = new String( "This is string one" );
var index = str1.indexOf( "string" );
document.write("indexOf found String :" + index ); 

document.write("<br />");

var index = str1.indexOf( "one" );
document.write("indexOf found String :" + index ); 


This will produce following result:

indexOf found String :8
indexOf found String :15 

To understand it in better way you can Try it yourself.

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