JavaScript String slice() method

Definition and Usage

slice() The method extracts a part of the string.

slice() The method returns the extracted part as a new string, without changing the original string.

start and end The parameter specifies the part of the string to be extracted.

The first position is 0, the second is 1, ...

Negative numbers start from the end of the string.

See also:

split() method

substr() method

substring() method

Instance

Example 1

Cut the first 5 positions:

let text = "Hello world!";
let result = text.slice(0, 5);

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Example 2

From position 3 to the end:

let result = text.slice(3);

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Example 3

From position 3 to 8:

let result = text.slice(3, 8);

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Example 4

Only the first character:

let result = text.slice(0, 1);

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Example 5

Only the last character:

let result = text.slice(-1);

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Example 6

The entire string:

let result = text.slice(0);

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Syntax

string.slice(start, end)

Parameter

Parameter Description
start

Required. Starting position.

The first character is 0.
end

Optional. End position (up to, but not including).

Default is the length of the string.

Return value

Type Description
string the part of the string extracted.

Technical details

Parameter start

This parameter is the starting index of the segment to be extracted. If it is negative, this parameter specifies the position from the end of the string. That is, -1 refers to the last character in the string, -2 refers to the second last character, and so on.

Parameter end

This parameter is the index of the end of the next segment to be extracted. start to the end of the original string. If this parameter is negative, it specifies the position from the end of the string.

Return value

a new string. Includes the string string from start (including startto end (excluding end(up to, but not including)

Description

The slice() method returns a string containing string a substring of the string, or return a substring of it. However, this method does not modify string.

methods of String objects slice(),substring() and substr()(not recommended for use) can all return a specified part of the string.slice() than substring() be more flexible, as it allows the use of negative numbers as parameters.slice() with substr() is different, as it uses two character positions to specify the substring, and substr() then specify the substring using character position and length.

It should also be noted that,String.slice() with Array.slice() similar.

browser support

slice() is an ECMAScript1 (ES1) feature.

All browsers fully support ES1 (JavaScript 1997):

Chrome IE Edge Firefox Safari Opera
Chrome IE Edge Firefox Safari Opera
support support support support support support

related pages

JavaScript String

JavaScript String Methods

JavaScript String Search