string.slice

The slice() method extracts a section of a string and returns it as a new string.

Syntax

str.slice(beginIndex[, endIndex])

Parameters

beginIndex

The zero-based index at which to begin extraction. If negative, it is treated as strLength + beginIndex where strLength is the length of the string (for example, if beginIndex is -3 it is treated as strLength - 3). If beginIndex is greater than or equal to the length of the string, slice() returns an empty string.

endIndex

Optional. The zero-based index before which to end extraction. The character at this index will not be included. If endIndex is omitted, slice() extracts to the end of the string. If negative, it is treated as strLength + endIndex where strLength is the length of the string (for example, if endIndex is -3 it is treated as strLength - 3).

Return value

A new string containing the extracted section of the string.

Description

slice() extracts the text from one string and returns a new string. Changes to the text in one string do not affect the other string.

slice() extracts up to but not including endIndex. str.slice(1, 4) extracts the second character through the fourth character (characters indexed 1, 2, and 3).

As an example, str.slice(2, -1) extracts the third character through the second to last character in the string.

Examples

Using slice() to create a new string

The following example uses slice() to create a new string.

var str1 = 'The morning is upon us.', // the length of str1 is 23.
    str2 = str1.slice(1, 8),
    str3 = str1.slice(4, -2),
    str4 = str1.slice(12),
    str5 = str1.slice(30);
console.log(str2); // OUTPUT: he morn
console.log(str3); // OUTPUT: morning is upon u
console.log(str4); // OUTPUT: is upon us.
console.log(str5); // OUTPUT: ""

Using slice() with negative indexes

The following example uses slice() with negative indexes.

var str = 'The morning is upon us.';
str.slice(-3);     // returns 'us.'
str.slice(-3, -1); // returns 'us'
str.slice(0, -1);  // returns 'The morning is upon us'

Specifications

Browser compatibility

See also

• String.prototype.substr()
• String.prototype.substring()
• Array.prototype.slice()