[ES6] ... spread operator

var parts = ['shoulders', 'knees'];

var lyrics = ['head', ...parts, 'and', 'toes']; // ["head", "shoulders", "knees", "and", "toes"]

var arr1 = [0, 1, 2];

var arr2 = [3, 4, 5];

arr1.push(...arr2); // [0,1,2,3,4,5

function myFunction(v, w, x, y, z) {

  console.log(v, w, x, y, z);

}

var args = [0, 1];

myFunction(-1, ...args, 2, ...[3]);]

//-1, 0 , 1, 2, 3