What are the call, apply, and bind methods used for in JavaScript?

They are used to control the execution context (the value of this) of a function.

• call: Invokes the function immediately with a specified this value and individual arguments.
• apply: Invokes the function immediately with a specified this value and arguments provided as an array or array-like object.
• bind: Creates a new function with a permanently bound this value and optionally preset arguments. The original function is not invoked immediately.

Main differences:

Method	How arguments are passed	Is the function invoked immediately?	Return value
call	Individually, separated by commas	Yes	Result of the function call
apply	As an array or array-like object	Yes	Result of the function call
bind	Individually, separated by commas	No	A new function with bound this

Usage examples:

const person = { name: 'Alice' };

function greet(greeting, punctuation) {
  return `${greeting}, ${this.name}${punctuation}`;
}

// Using call
console.log(greet.call(person, 'Hello', '!')); // Output: Hello, Alice!

// Using apply
console.log(greet.apply(person, ['Hi', '.'])); // Output: Hi, Alice.

// Using bind
const boundGreet = greet.bind(person, 'Bonjour');
console.log(boundGreet('!')); // Output: Bonjour, Alice!

const anotherBoundGreet = greet.bind(person, 'Hola', '?');
console.log(anotherBoundGreet()); // Output: Hola, Alice?