Check If A Set Contains An Object In JavaScript

In this article, we will cover how to check if a Set contains an object in JavaScript. To achieve this, we need to use the `has()` method on our `Set` and pass the object as an argument. The `has()` method returns `true` if the object exists inside the `Set` or `false` if the object does not exist.

First, let’s start by creating two objects and initializing them with values –

const obj = {

  key: "value"


const anotherObj = {

  key: "value"


Then, let’s create a `Set` using the `Set()` constructor and assign our first object `obj` to it.

const set = new Set([obj]);

Now, to check if our object exists inside the set, we will call the `has()` method on the `set`, passing in our object as an argument, and then we will print the output on the console.

true is returned as set contains the object

As we can see, we got `true` on the console as our object `obj` exists in `set`. Let’s do the same check for the second object `anotherObject` and see what we get on the console.

false is returned as the set doesn't contain the object

Since, `anotherObject` does not exist in `set`, the `has()` method returned `false` as a result.

Finally, we can wrap this logic inside of a function so that we can pass any object and set we need, and check if the object exists inside the set –

const isObjectInSet = (set, object) => {

return set.has(object);


Now, let’s call our function passing in `set` and `obj` as arguments and print the result on the console –

console.log(isObjectInSet(set, obj));
function returns true since set contains object

Leave a Comment