ES6 : Rest Operator

Rest Operator

Rest Operator ... converts the rest parameters to JavaScript array.

1. Without rest operator

function printNums(num1, num2) {
  console.log(num1, num2);
}

printNums(1, 2, 3, 4, 5);

1 2

2. arguments is the object of all the parameters.

function printNums(num1, num2) {
  console.log(arguments);
}

printNums(1, 2, 3, 4, 5);

[Arguments] { '0': 1, '1': 2, '2': 3, '3': 4, '4': 5 }

3. ... is combine the rest parameters as an object.

function printNums(num1, ...num2) {
  console.log(num1, num2);
}

printNums(1, 2, 3, 4, 5);

1 [ 2, 3, 4, 5 ]