What is collation

Collation is used for sorting a set of strings and searching within a set of strings. It is parameterized by locale and aware of Unicode. Let's take comparison and sorting features,

1. Comparison:

var list = ["ä", "a", "z"]; // In German,  "ä" sorts with "a" Whereas in Swedish, "ä" sorts after "z"
var l10nDE = new Intl.Collator("de");
var l10nSV = new Intl.Collator("sv");
console.log(l10nDE.compare("ä", "z") === -1); // true
console.log(l10nSV.compare("ä", "z") === +1); // true

2. Sorting:

var list = ["ä", "a", "z"]; // In German,  "ä" sorts with "a" Whereas in Swedish, "ä" sorts after "z"
var l10nDE = new Intl.Collator("de");
var l10nSV = new Intl.Collator("sv");
console.log(list.sort(l10nDE.compare)); // [ "a", "ä", "z" ]
console.log(list.sort(l10nSV.compare)); // [ "a", "z", "ä" ]