4.What is JSON and its common operations

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy to read and write for humans and easy to parse and generate for machines. It is widely used for data exchange between a server and a web application, as well as for configuration files, APIs, and database storage.

JSON represents data in key-value pairs, using:

• Objects (enclosed in {}) with key-value pairs.
• Arrays (enclosed in []) containing multiple values.

Example of JSON:

json
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{
  "name": "John Doe",
  "age": 30,
  "isStudent": false,
  "hobbies": ["reading", "gaming", "traveling"],
  "address": {
    "city": "New York",
    "zip": "10001"
  }
}

Common JSON Operations:

1. Parsing JSON (String to Object)

Converting a JSON string into a JavaScript object.

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const jsonString = '{"name":"John", "age":30}';
const obj = JSON.parse(jsonString);
console.log(obj.name); // Output: John

2. Stringifying JSON (Object to String)

Converting a JavaScript object into a JSON string.

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const obj = { name: "John", age: 30 };
const jsonString = JSON.stringify(obj);
console.log(jsonString); // Output: {"name":"John","age":30}

3. Accessing JSON Data

Once parsed, JSON data can be accessed like a normal JavaScript object.

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const person = {
  name: "Alice",
  age: 25,
  address: { city: "Los Angeles", zip: "90001" }
};

console.log(person.name); // Output: Alice
console.log(person.address.city); // Output: Los Angeles

4. Modifying JSON Data

You can modify JSON objects directly.

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person.age = 26;
person.address.city = "San Francisco";
console.log(person);

5. Adding and Removing Properties

• Adding a property

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person.email = "alice@example.com";
console.log(person);

• Removing a property

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delete person.age;
console.log(person);

6. Looping Through JSON Data

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for (let key in person) {
  console.log(`${key}: ${person[key]}`);
}

7. Handling Nested JSON Data

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const data = {
  users: [
    { id: 1, name: "Alice" },
    { id: 2, name: "Bob" }
  ]
};

console.log(data.users[1].name); // Output: Bob

Where is JSON Used?

• APIs: Used for data exchange in web applications.
• Configuration Files: .json files for storing settings.
• Databases: NoSQL databases like MongoDB use JSON-like formats.
• Local Storage: Web storage in browsers (localStorage).

Let me know if you need further details! 🚀