when were arrow functions introduced js code example

Example 1: javascript arrow function

// Non Arrow (standard way)
let add = function(x,y) {
  return x + y;
}
console.log(add(10,20)); // 30

// Arrow style
let add = (x,y) => x + y;
console.log(add(10,20)); // 30;

// You can still encapsulate
let add = (x, y) => { return x + y; };

Example 2: js arrow function

// const add = function(x,y) {
//     return x + y;
// }

// const add = (x, y) => {
//     return x + y;
// }

const add = (a, b) => a + b;


const square = num => {
    return num * num;
}

// const rollDie = () => {
//     return Math.floor(Math.random() * 6) + 1
// }

const rollDie = () => (
    Math.floor(Math.random() * 6) + 1
)