Object Rest/Spread Properties code example

Example 1: spread operator javascript

obj = {first_name : "Marty",
    lovers: ["Jennifer Parker","Baines McFly"]
      };
let objClone = { ...obj }; // pass all key:value pairs from an object 

console.log(objClone)
// { first_name: "Marty", lovers: ["Jennifer Parker", "Baines McFly"] }

Example 2: spread operator

function sum(x, y, z) {
  return x + y + z;
}

const numbers = [1, 2, 3];

console.log(sum(...numbers));
// expected output: 6

console.log(sum.apply(null, numbers));
// expected output: 6