# call() and apply() in JavaScript

> Learn how to use call() and apply() in JavaScript to invoke a function with a chosen this value, where call() takes a list and apply() takes an array.

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2018-12-10 | Topics: [JavaScript](https://flaviocopes.com/tags/js/) | Canonical: https://flaviocopes.com/javascript-call-apply/

call() and apply() are two functions that [JavaScript](https://flaviocopes.com/javascript/) offers to perform a very specific task: call a function and set its `this` value.

> Check out my ["this" guide](https://flaviocopes.com/javascript-this/) to know all the details about this particular variable

A function can use the `this` value for many different use cases. The problem is that it's given by the environment and cannot be changed from the outside, except when using `call()` or `apply()`.

When using those methods, you can pass in an additional object that will be used as `this` in the function invoked.

Those functions perform the same thing, but have a difference. In `call()` you can pass the function parameters as a comma separated list of parameters, taking as many parameters as you need, while in `apply()` you pass a single array that contains the parameters:

```js
const car = {
  brand: 'Ford',
  model: 'Fiesta'
}

const drive = function(from, to, kms) {
  console.log(`Driving for ${kms} kilometers from ${from} to ${to} with my car, a ${this.brand} ${this.model}`)
}

drive.call(car, 'Milan', 'Rome', 568)
drive.apply(car, ['Milan', 'Rome', 568])
```

Note that when using [arrow functions](https://flaviocopes.com/javascript-arrow-functions/) `this` is not bound, so this method only works with regular functions.