Sorting by Local Habits

Use Cases

The sorting function allows list content, for example, the language list in Settings, to be sorted and displayed in line with local user habits.

How to Develop

The sorting function is implemented by the compare API of the Collator class. The development procedure is as follows:

Import the intl module.
```
import Intl from '@ohos.intl';
```
Create a Collator object. You can use CollatorOptions to set different sorting formats. For details, see Table 1.
```
let collator = new Intl.Collator(locale: string | Array<string>, options?: CollatorOptions);
```

Compare strings.

let compareResult = collator.compare("first", "second");

// If compareResult is a negative number, the first parameter is placed before the second parameter.
// If compareResult is 0, the first and second parameters are not sorted in sequence.
// If compareResult is a positive number, the first parameter is placed after the second parameter.

Sorting Format Options

Table 1 Supported sorting formats and display effects

Name	Value	Description	Display Effect
localeMatcher	lookup	Fuzzy matching.
	best fit	Exact matching.
usage	sort	Sorting.
	search	Search for matched strings.
sensitivity	base	Compare different letters.	Example: a ≠ b, a = á, a = A
	accent	Compare different letters or accents.	Example: a ≠ b, a ≠ á, a = A
	case	Compare the capitalization of different letters or the same letter.	Example: a ≠ b, a = á, a = A
	variant	Compare different letters or accents, and other distinctive signs or capitalization.	Example: a ≠ b, a ≠ á, a ≠ A
ignorePunctuation	true	Ignore punctuation.	a,b = ab
	false	Not ignore punctuation.	a,b < ab
numeric	true	Sort by number.	1 < 2 < 10 < 11
	false	Not sort by number.	1 < 10 < 11 < 2
caseFirst	upper	Place uppercase letters in the front.	ab,aB, AB,Ab => AB < Ab < aB < ab
	lower	Place lowercase letters in the front.	ab,aB, AB,Ab => ab < aB < Ab < AB
	false	Not distinguish first letter capitalization.	ab,aB, AB,Ab => ab < aB < Ab < AB
collation	big5han	Pinyin sorting for Latin letters.
	compat	Compatibility sorting, only for Arabic.
	dict	Dictionary-style sorting, only for Singhalese.
	direct	Binary code sorting.
	ducet	Default Unicode collation element table.
	eor	European sorting.
	gb2312	Pinyin sorting, only for Chinese.
	phonebk	Phonebook-style sorting.
	phonetic	Phonetic sorting.
	pinyin	Pinyin sorting.
	reformed	Reformed sorting, only for Swedish.
	searchjl	Special collation type for Korean initial consonant search.
	stroke	Stroke sorting for Chinese.
	trad	Traditional-style sorting, for example, Spanish.
	unihan	Radical-stroke sorting for Han characters, only for Chinese, Japanese, and Korean.
	zhuyin	Zhuyin sorting, only for Chinese.

Development Example

// Import the i18n module.
import I18n from '@ohos.i18n';
import Intl from '@ohos.intl';

// Create a Collator object.
let options: Intl.CollatorOptions = {
    localeMatcher: "lookup", 
    usage: "sort",
    sensitivity: "case" // Case sensitive
};
let collator = new Intl.Collator("zh-CN", options);

// Case-sensitive sorting
let array = ["app", "App", "Apple", "ANIMAL", "animal", "apple", "APPLE"];
array.sort((a, b) => {
    return collator.compare(a, b);
})
console.log("result: ", array);  // animal ANIMAL app App apple Apple APPLE

// Pinyin sorting for Chinese
array = ["Pingguo", "Li", "Xiangjiao", "Shiliu", "Ganzhe", "Putao", "Juzi"];
array.sort((a, b) => {
    return collator.compare(a, b);
})
console.log("result:", array); // Ganzhe, Juzi, Li, Pingguo, Putao, Shiliu, Xiangjiao

// Stroke sorting
options = {
    localeMatcher: "lookup", 
    usage: "sort",
    collation: "stroke"
};
collator = new Intl.Collator("zh-CN", options);
array = ["苹果", "梨", "香蕉", "石榴", "甘蔗", "葡萄", "橘子"];
array.sort((a, b) => {
    return collator.compare(a, b);
})
console.log("result:", array); // 甘蔗,石榴,苹果,香蕉,梨,葡萄,橘子