Objects & JSON

An Object is a collection of "key-value" pairs. Instead of using a number to find data (like in an array), you use a name (a key). JSON (JavaScript Object Notation) is just a string format of this data used to send info over the internet.

1. Object Literals

Created using curly braces {}. Inside, you define a key: value.

• Properties: The data stored (e.g., name: "Gemini").

• Methods: Functions stored inside an object (e.g., greet: function() { ... }).

2. Accessing Data

• Dot Notation: user.name (Most common).

• Bracket Notation: user["name"] (Useful if the key is stored in a variable).

3. JSON

The format almost every API uses. It looks exactly like a JS object but keys must be in double quotes.

The Code Example

// 1. Creating an Object
const smartPhone = {
    brand: "Apple",
    model: "iPhone 15",
    batteryPct: 85,
    is5G: true,
    
    // 2. Adding a Method (A function inside an object)
    ring: function() {
        console.log("Ring ring! 🔔");
    }
};

// 3. Accessing and Modifying
console.log(smartPhone.brand); // "Apple"
smartPhone.batteryPct = 90;    // Updating a value
smartPhone.color = "Space Gray"; // Adding a new property

smartPhone.ring(); // Calling the method

// 4. JSON Conversion (Sending/Receiving data)
const jsonString = JSON.stringify(smartPhone); // Object to String
console.log(jsonString);

const backToObject = JSON.parse(jsonString);   // String back to Object