ReasonJun

spread const a = [1, 2, 3]; console.log(...a); // 1 2 3 const b = [4, 5, 6]; const c = a.concat(b); console.log(c); // [ 1, 2, 3, 4, 5, 6 ] const d = [a, b]; console.log(d); // [ [ 1, 2, 3 ], [ 4, 5, 6 ] ] const e = [...a, ...b]; console.log(e); // [ 1, 2, 3, 4, 5, 6 ] const aa = { x: 1, y: 2 }; const bb = { y: 3, z: 4 }; const cc = Object.assign({}, aa, bb); console.log(cc); // { x: 1, y: 3, z:..