JavaScript String localeCompare() method

Definition and usage

localeCompare() The method compares two strings in the current language environment.

localeCompare() The method returns the sorting order -1,1 or 0（Indicates before, after, or equal).

The current language environment is based on the browser's language settings.

Example

Example 1

Compare "ab" and "cd":

let text1 = "ab";
let text2 = "cd";
let result = text1.localeCompare(text2);

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Example 2

let text1 = "cd";
let text2 = "ab";
let result = text1.localeCompare(text2);

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Example 3

let text1 = "ab";
let text2 = "ab";
let result = text1.localeCompare(text2);

Example 4

Try it yourself

let text1 = "A";
let text2 = "a";
let result = text1.localeCompare(text2);

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Syntax

string.localeCompare(target)

Parameter

Parameter Description
target Required. The string to be compared.

Return value

Type Description
Number

One of the 3 values:

  • -1, if the string is sorted before the target
  • 　0, if the two strings are equal
  • 　1, if the string is sorted after the target

Technical details

Return value

returns the number that indicates the comparison result.

If string less than targetThen localeCompare() returns a number less than 0.

If string greater than targetThen this method returns a number greater than 0.

If two strings are equal, or do not differ according to the local sorting rules, this method returns 0.

Explain

to < and > When the operator is applied to a string, it compares strings using only the Unicode encoding of characters, without considering the local sorting rules. The order generated in this way may not be correct. For example, in Spanish, the character 'ch' is usually sorted as a character between 'c' and 'd'.

localeCompare() method provides a way to compare strings, taking into account the default local sorting rules. The ECMAScript standard does not specify how to perform a local-specific comparison operation; it only specifies that this function uses the sorting rules provided by the underlying operating system.

Browser support

localeCompare() is a feature of ECMAScript1 (ES1).

All web browsers fully support ES1 (JavaScript 1997):

Chrome IE Edge Firefox Safari Opera
Chrome IE Edge Firefox Safari Opera
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Relaterade sidor

JavaScript-sträng

JavaScript-strängmetoder

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