indexOf

Summary

Returns the position of the first occurrence of a substring.

Syntax

strObj. indexOf( subString [, startIndex ])

strObj

Required. A String object or string literal.

subString

Required. The substring to search for in the string

startIndex

Optional. The index at which to begin searching the String object. If omitted, search starts at the beginning of the string.

Examples

The following example illustrates the use of the indexOf method.

var str = "original equipment manufacturer";

 var s = "equip is at position " + str.indexOf("equip");
 s += "<br />";
 s += "abc is at position " + str.indexOf("abc");

 document.write(s);

 // Output:
 // equip is at position 9
 // abc is at position -1

Remarks

The indexOf method returns the beginning of the substring in the String object. If the substring is not found, -1 is returned.

If startindex is negative, startindex is treated as zero. If it is greater than the highest index, it is treated as the highest index.

Searching is performed from left to right. Otherwise, this method is identical to lastIndexOf.

See also

Other articles

• lastIndexOf Method (String)

Attributions

• Microsoft Developer Network: Article