JavaScript String substr() Method

substr()The method returns a substring of a specified length starting from a specified position.

The index of the first character is 0, the index of the second character is1and so on.

To extract characters from the end of a string, please use negative index numbers (see the 'More Examples' below).

Syntax:

string.substr(index, length)

Example

var　str1　=　'Air Pollution is introduction of chemicals to the atmosphere.';
var　str2　=　str1.substr(7);

All browsers fully support the substr() method:

Method
substr()	Yes	Yes	Yes	Yes	Yes

Parameter	Description
index	(Required) The index of the first character to include in the returned substring
length	(Optional) The number of characters to extract. If length is omitted, substr() extracts characters to the end of the string

Return Value:	A new string containing the specified part of the given string
JavaScript Version:	ECMAScript 1

The following example uses substr() from index4Extract characters, length of18:

Example

var　str1　=　'Air Pollution is introduction of chemicals to the atmosphere.';
var　str2　=　str1.substr(4,　18);

The following example uses substr() with a negative index:

Example

var　str1　=　'www.oldtoolbag.com';
var　str2　=　str1.substr(-6,　3);　　　//　tor