Top 10 JavaScript concepts and functionalities Q

Here are the top 10 examples of JavaScript code snippets that demonstrate different fundamental concepts and functionalities of the language:

1. Variable Declaration

let name = "Alice";
const age = 25;
var isStudent = true;

console.log(name, age, isStudent);

2. Functions

function greet(person) {
    return `Hello, ${person}!`;
}

console.log(greet("Bob"));

3. Arrow Functions

const sum = (a, b) => a + b;

console.log(sum(5, 3));

4. Array Methods

let numbers = [1, 2, 3, 4, 5];
let squares = numbers.map(num => num * num);

console.log(squares); // [1, 4, 9, 16, 25]

5. Object Literals

let person = {
    name: "Charlie",
    age: 30,
    greet() {
        console.log(`Hi, my name is ${this.name}`);
    }
};

person.greet(); // Hi, my name is Charlie

6. Promises

let promise = new Promise((resolve, reject) => {
    setTimeout(() => {
        resolve("Data fetched successfully!");
    }, 2000);
});

promise.then(message => {
    console.log(message);
});

7. Async/Await

async function fetchData() {
    let data = await fetch('https://jsonplaceholder.typicode.com/todos/1');
    let json = await data.json();
    console.log(json);
}

fetchData();

8. Event Handling

document.getElementById("myButton").addEventListener("click", () => {
    alert("Button was clicked!");
});

9. DOM Manipulation

let newElement = document.createElement("div");
newElement.textContent = "Hello, World!";
document.body.appendChild(newElement);

10. Class

class Animal {
    constructor(name) {
        this.name = name;
    }

    speak() {
        console.log(`${this.name} makes a sound`);
    }
}

let dog = new Animal("Dog");
dog.speak(); // Dog makes a sound