Default Parameters

Give a parameter a fallback when no argument is passed.

default_params.js

function addTax(amount, rate = 10) {
  return amount + (amount * rate) / 100;
}

const base = ;
const withDefault = addTax(base);
const withRate = addTax(base, 25);

console.log("withDefault=" + withDefault);
console.log("withRate=" + withRate);

function addTax(amount, rate = 10) {
  return amount + (amount * rate) / 100;
}

const base = ;
const withDefault = addTax(base);
const withRate = addTax(base, 25);

console.log("withDefault=" + withDefault);
console.log("withRate=" + withRate);

function addTax(amount, rate = 10) {
  return amount + (amount * rate) / 100;
}

const base = ;
const withDefault = addTax(base);
const withRate = addTax(base, 25);

console.log("withDefault=" + withDefault);
console.log("withRate=" + withRate);

default-params A default parameter supplies a value when the caller omits that argument. Passing the argument explicitly overrides the default.