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Other References

CSSStyleDeclaration JS Conversion


JavaScript String indexOf() Method

Example

Search a string for "welcome":

var str = "Hello world, welcome to the universe.";
var n = str.indexOf("welcome");
Try it Yourself »

More "Try it Yourself" examples below.


Definition and Usage

The indexOf() method returns the position of the first occurrence of a specified value in a string.

This method returns -1 if the value to search for never occurs.

Note: The indexOf() method is case sensitive.

Tip: Also look at the lastIndexOf() method.


Browser Support

Method
indexOf() Yes Yes Yes Yes Yes

Syntax

string.indexOf(searchvalue, start)

Parameter Values

Parameter Description
searchvalue Required. The string to search for
start Optional. Default 0. At which position to start the search


Technical Details

Return Value: A Number, representing the position where the specified searchvalue occurs for the first time, or -1 if it never occurs
JavaScript Version: ECMAScript 1

More Examples

Example

Find the first occurrence of the letter "e" in a string:

var str = "Hello world, welcome to the universe.";
var n = str.indexOf("e");
Try it Yourself »

Example

Find the first occurrence of the letter "e" in a string, starting the search at position 5:

var str = "Hello world, welcome to the universe.";
var n = str.indexOf("e", 5);