ES2015で追加された分割代入

分割代入の一例

let data = [1, 2, 3, 4, 5, 6, 7];

let [num1, num2, num3, num4, num5, num6, num7] = data;

console.log(num1); //1
console.log(num2); //2
console.log(num7); //7

let data = [1, 2, 3, 4, 5, 6, 7];

「...」演算子を利用した例

let data = [1, 2, 3, 4, 5, 6, 7];

let [num1, num2, num3, ...rest_num] = data;
console.log(num1); //1
console.log(num2); //2
console.log(rest_num); //[4, 5, 6, 7];
console.log(rest_num[0]); //4