Destructuring an array

Version ≥ 6 An array can be destructured when being assigned to a new variable.

const triangle = [3, 4, 5];
const [length, height, hypotenuse] = triangle;
length === 3; // → true height === 4; // → true hypotneuse === 5; // → true

Elements can be skipped

const [,b,,c] = [1, 2, 3, 4]; 
console.log(b, c); // → 2, 4

Rest operator can be used too

 const [b,c, ...xs] = [2, 3, 4, 5]; 
 console.log(b, c, xs); // → 2, 3, [4, 5]

An array can also be destructured if it's an argument to a function.

function area([length, height]) { 
    return (length * height) / 2;
}
const triangle = [3, 4, 5]; 
area(triangle); // → 6

Notice the third argument is not named in the function because it's not needed.

Learn more about destructuring syntax.