JS Practice — Built-in Objects

isPrototypeOf() — deeper chain

📖 Usage Example

// Check prototype chain membership
const proto = {}
const child = Object.create(proto)
proto.isPrototypeOf(child)   // → true
Object.prototype.isPrototypeOf(child)  // → true

Use isPrototypeOf() to check whether an object exists anywhere in the prototype chain of another object.

isPrototypeOf() — multi-level chain

isPrototypeOf() checks the entire chain, not just the immediate prototype. So if A → B → C, A.isPrototypeOf(C) returns true.

Challenge: Verify that isPrototypeOf works across multiple levels.

💡 Hints (1)

• isPrototypeOf checks the entire chain, not just the immediate parent