how to check if key exists in an object (Javascript)

Let’s learn how you can check if a key exists in two different ways
Both are very easy.

Firstly let’s define our object

const car = {
  brand: "Fiat",
  model: "500",
  hp: 21,
  year: 1960,
}

1. in Operator

just type the key in a string and use “in” with an object

const hasKeyBrand = "brand" in car
// true

Here we will use the dedicated function hasOwnProperty()

const hasKeyBrand = car.hasOwnProperty("brand");
// true

And there you go, that’s how you check if the key exists in a javascript array.