Difference between call, apply, and bind in JavaScript

Question

What’s the difference between call, apply, and bind in JavaScript?

Answer

All three explicitly set the value of this for a function.

const user = { name: 'Ghazi' };
function greet(greeting) {
  console.log(`${greeting}, ${this.name}`);
}

greet.call(user, 'Hello');
greet.apply(user, ['Hi']);
const bound = greet.bind(user);
bound('Hey');

• call(): calls the function immediately, with arguments separated by commas.
• apply(): same as call, but arguments are passed as an array.
• bind(): returns a new function with a permanently bound this.

Real-World Example

In event listeners or callbacks, bind ensures your function retains its intended context.

Quick Practice

Create a function that logs a message using this.name and test it with all three methods.

Summary

Use call and apply to invoke immediately, bind to remember context.