Functions

Default and Rest Parameters

Default values

function greet(name = "friend", greeting = "Hello") {
  return `${greeting}, ${name}!`;
}
console.log(greet());            // Hello, friend!
console.log(greet("Sara", "Hi")); // Hi, Sara!

Rest parameters

... collects any number of arguments into an array.

function total(...prices) {
  return prices.reduce((sum, p) => sum + p, 0);
}
console.log(total(100, 250, 400));

Output