Intl.Collator() constructor

The Intl.Collator() constructor creates Intl.Collator objects that enable language-sensitive string comparison.

Syntax

new Intl.Collator()
new Intl.Collator(locales)
new Intl.Collator(locales, options)

Parameters

locales Optional

Optional. A string with a BCP 47 language tag, or an array of such strings. For the general form and interpretation of the locales argument, see the Intl page.

The following Unicode extension keys are allowed:

Note: These keys can usually also be set with options (as listed below). When both are set, the options property takes precedence.

co

Variant collations for certain locales. Possible values include:

• big5han
• compat
• dict
• direct
• ducet
• eor
• gb2312
• phonebk(only supported in German)
• phonetic
• pinyin
• reformed
• searchjl
• stroke
• trad
• unihan
• zhuyin

Note: This option can be also be set through the options property "collation".

kn

Whether numeric collation should be used, such that "1" < "2" < "10". Possible values are "true" and "false". This option can be also be set through the options property "numeric".

kf

Whether upper case or lower case should sort first. Possible values are "upper", "lower", or "false" (use the locale's default). This option can be also be set through the options property "caseFirst".

options Optional

An object with some or all of the following properties:

localeMatcher

The locale matching algorithm to use. Possible values are "lookup" and "best fit"; the default is "best fit". For information about this option, see the Intl page.

usage

Whether the comparison is for sorting or for searching for matching strings. Possible values are "sort" and "search"; the default is "sort".

sensitivity

Which differences in the strings should lead to non-zero result values. Possible values are:

• "base": Only strings that differ in base letters compare as unequal. Examples: a ≠ b, a = á, a = A.
• "accent": Only strings that differ in base letters or accents and other diacritic marks compare as unequal. Examples: a ≠ b, a ≠ á, a = A.
• "case": Only strings that differ in base letters or case compare as unequal. Examples: a ≠ b, a = á, a ≠ A.
• "variant": Strings that differ in base letters, accents and other diacritic marks, or case compare as unequal. Other differences may also be taken into consideration. Examples: a ≠ b, a ≠ á, a ≠ A.

The default is "variant" for usage "sort"; it's locale dependent for usage "search".

ignorePunctuation

Whether punctuation should be ignored. Possible values are true and false; the default is false.

numeric

Whether numeric collation should be used, such that "1" < "2" < "10". Possible values are true and false; the default is false.

Note: This option can also be set through the kn Unicode extension key; if both are provided, this options property takes precedence.

caseFirst

Whether upper case or lower case should sort first. Possible values are "upper", "lower", or "false" (use the locale's default). This option can be set through an options property or through a Unicode extension key; if both are provided, the options property takes precedence.

Note: This option can also be set through the kf Unicode extension key; if both are provided, this options property takes precedence.

collation

Variant collations for certain locales. Possible values include:

• big5han
• compat
• dict
• direct
• ducet
• eor
• gb2312
• phonebk(only supported in German)
• phonetic
• pinyin
• reformed
• searchjl
• stroke
• trad
• unihan
• zhuyin

Note: This option can also be set through the co Unicode extension key; if both are provided, this options property takes precedence.

Examples

Using Collator

The following example demonstrates the different potential results for a string occurring before, after, or at the same level as another:

console.log(new Intl.Collator().compare('a', 'c')); // → a negative value
console.log(new Intl.Collator().compare('c', 'a')); // → a positive value
console.log(new Intl.Collator().compare('a', 'a')); // → 0

Note that the results shown in the code above can vary between browsers and browser versions. This is because the values are implementation-specific. That is, the specification requires only that the before and after values are negative and positive.

Specifications

Browser compatibility

See also

• Intl.Collator
• Intl