Q134- What is the difference between bind(), call(), and apply() in JavaScript?

All three methods are used to set the value of this inside a function, but they differ in how and when the function is invoked.

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1️⃣ call()

• Invokes the function immediately.
• Arguments are passed individually (comma-separated).

Example:

const person = { name: "Alice" };

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

greet.call(person, "Hello", "!"); // Hello, Alice!

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2️⃣ apply()

• Invokes the function immediately.
• Arguments are passed as an array.

Example:

greet.apply(person, ["Hi", "!!"]); // Hi, Alice!!

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3️⃣ bind()

• Returns a new function with this bound to the specified object.
• Does not call the function immediately.
• Arguments can be passed now or later when calling the bound function.

Example:

const greetAlice = greet.bind(person, "Hey");
greetAlice("?"); // Hey, Alice?

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⚖️ Comparison Table

Method	Calls Function Immediately?	Arguments Format	Returns New Function?
call	✅ Yes	Comma-separated	❌ No
apply	✅ Yes	Array	❌ No
bind	❌ No	Comma-separated (partial)	✅ Yes

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🧩 In Short:

• call() → call now, args separately
• apply() → call now, args as array
• bind() → create a new function with bound this, call later

This is useful for function borrowing, partial application, and controlling the this context in JavaScript.