Clone an array

JavaScript version

// `arr` is an array
const clone = (arr) => arr.slice(0);

// Or
const clone = (arr) => [...arr];

// Or
const clone = (arr) => Array.from(arr);

// Or
const clone = (arr) => arr.map((x) => x);

// Or
const clone = (arr) => JSON.parse(JSON.stringify(arr));

// Or
const clone = (arr) => arr.concat([]);

TypeScript version

// `arr` is an array
const clone = <T,_>(arr: T[]): T[] => arr.slice(0);

// Or
const clone = <T,_>(arr: T[]): T[] => [...arr];

// Or
const clone = <T,_>(arr: T[]): T[] => Array.from(arr);

// Or
const clone = <T,_>(arr: T[]): T[] => arr.map((x) => x);

// Or
const clone = <T,_>(arr: T[]): T[] => JSON.parse(JSON.stringify(arr));

// Or
const clone = <T,_>(arr: T[]): T[] => arr.concat([]);

Check if an array is empty

Compare two arrays regardless of order