JavaScript Object Manipulation: Your Survival Guide

JavaScript objects are like clay - they can be shaped, protected, and copied in ways you might not expect. Let's break down the magic!

Protecting Your Objects: Freeze vs Seal

Object.freeze() 🧊

const frozenObject = { name: "Elsa" };
Object.freeze(frozenObject);

frozenObject.name = "Anna"; // Nope! 
console.log(frozenObject.name); // Still "Elsa"

Object.seal() 🛡️

const sealedObject = { name: "Jack" };
Object.seal(sealedObject);

sealedObject.name = "New Name"; // Works
sealedObject.age = 30; // Blocked!

Key Difference:

freeze(): Prevents ALL changes
seal(): Allows value modifications, blocks new properties

Cloning: Shallow vs Deep

Shallow Clone

const original = { 
    user: { name: "Alice" },
    age: 30 
};
const shallowCopy = { ...original };

shallowCopy.user.name = "Bob";
console.log(original.user.name); // "Bob" (!) - nested objects still linked

Deep Clone

const deepCopy = JSON.parse(JSON.stringify(original));
// Now changes to nested objects won't affect the original

Immutability Patterns

// Immutable update
const updateUser = (user, updates) => ({
    ...user,
    ...updates
});

const alice = { name: "Alice", age: 30 };
const updatedAlice = updateUser(alice, { age: 31 });