EcmaScript | ES6 extended_parameters.js

// Default parameters
const add = (a, b = 1) => a + b

console.log(add(1,5)) // Expected output: 6
console.log(add(1)) // Expected output: 2

// Rest parameters
const myFunc = (a, ...rest) => {
  console.log(rest)
}

myFunc(1,2,3) // Expected output: [2, 3]
myFunc(1,2,3,4,5) // Expected output: [2, 3, 4, 5]

// Spread operator
const sum = (a, b, c) => a + b + c
console.log(sum(...[1,2,3])) // Expected output: 6
const arr = [2,6,4,8,3,1,5]
console.log(Math.max(...arr)) // Expected output: 8