JavaScript String substring() Method

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JavaScript String substring() Method

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Example

Extract characters from a string:

var str = "Hello world!";
var res = str.substring(1, 4);

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The result of res will be:

ell

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Try it Yourself »

More "Try it Yourself" examples below.

Definition and Usage

The substring() method extracts the characters from a string, between two specified indices,
and returns the new sub string.

This method extracts the characters in a string between "start" and "end", not
including "end" itself.

If "start" is greater than "end", this method will swap the two arguments,
meaning str.substring(1, 4) == str.substring(4, 1).

If either "start" or "end" is less than 0, it is treated as if it were 0.

Note: The substring() method does not change the original
string.

Browser Support

Method
substring()	Yes	Yes	Yes	Yes	Yes

Syntax

string.substring(start, end)

Parameter Values

Parameter	Description
start	Required. The position where to start the extraction. First character is at index 0
end	Optional. The position (up to, but not including) where to end the extraction. If omitted, it extracts the rest of the string

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Technical Details

Return Value:	A new String containing the extracted characters
JavaScript Version:	ECMAScript 1

More Examples

Example

Begin the extraction at position 2, and extract the rest of the string:

var str = "Hello world!";

var res = str.substring(2);

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The result of res will be:

llo world!

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Try it Yourself »

Example

If "start" is greater than "end", it will swap the two arguments:

var str = "Hello world!";
var res = str.substring(4, 1);

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The result of res will be:

ell

-->
Try it Yourself »

Example

If "start" is less than 0, it will start extraction from index
position 0:

var str = "Hello world!";

var res = str.substring(-3);

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The result of res will be:

Hello world!

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Try it Yourself »

Example

Extract only the first character:

var str = "Hello world!";

var res = str.substring(0, 1);

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The result of res will be:

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Try it Yourself »

Example

Extract only the last character:

var str = "Hello world!";

var res = str.substring(str.length - 1, str.length);

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The result of res will be:

-->
Try it Yourself »

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