all.js

// Variable Declarations
let x;// Declares a block-scoped variable
const y = 10; // Declares a block-scoped. read-only constant
// Functions
function myFunction() {
	//Function declaration
}
const myFunction = () = {
	//Arrow unction exeression
}
// Conditional Statements
if (condition) {
	// Executes if condition is true
}else if (otherCondition) {
	// Executes if otherCondition is true
} else {
	// Executes if all conditions are false
}
// Loops
for (let i = 0; i < 10; i++) {
	// For loop; repeats code while a condition is true
}
while (condition) {
	// While loop; repeats code while condition is true
}
do {
	//Executes code block at least once, then repeats while condition is true
} while (condition);
// Array Methods
let arr = [1, 2, 3];
arr.push(4); // Adds an element to the end of the array
arr.pop(); // Removes the last element from the array
arr.shift(); // Removes the first element from the array
arr.unshift(0); // Adds an element to the beginning of the array
// Object Methods
let obj = { name: 'John', age: 30 };
Object.keys(obj);// Returns an array of the object's keys
Object.values(obj ); // Returns an array of the object's values
Object.entries(obj); // Returns an array of the object's key-value pairs
// String Methods
let str = "Hello, world!";
str.length; // Returns the length of the string
str.toUpperCase(); // Converts string to uppercase 
str.toLowerCase(); // Converts string to lowercase 
str.includes("world"); // Checks if the string contains "world"

//DOM Manipulation
document.getElementById('id'); // Selects an element by its ID
document.querySelector('.class'); // Selects the first element that matches the CSS selector
document.querySelectorAll( 'div'); // Selects all elements that match the CSS selector
document.createElement('div'); //creates a new HTML element

// Event Listeners
element.addEventListener ('click', function); // Attaches a click event listener to an element
//JSON Methods
JSON.stringify(obj); // Converts a JavaScript object to a JSON string
JSON.parse(jsonStr); // Parses a JSON string into a JavaScript object
// Asynchronous Operations
fetch(url)
	.then response = response.json()) // Performs a network request and returns a promise
•then(data = console.log(data))
•catch(error = console.error(error)); // Catches errors in the fetch process

async function fetchData(){
	// Declares an asynchronous function
	try {
		let response = await fetch(url): // Waits for the fetch to complete
		let data = await response.json(); // Waits for the response to be parsed
		console. log(data); // Logs the data
	} catch (error) {
		console.error(error); // Catches and logs any errors
	}
}
// Date and Time
let now = new Date(); // Creates a new date object representing the current date and
now.getFullYear(); // Gets the four-digit year
now.getMonth(); // Gets the month (0-11, January is 0)
now.getDate(); // Gets the day of the month (1-31)
now.getHours(); // Gets the hour (0-23)
now.getMinutes(); // Gets the minutes(0-59)
now.getSeconds(); // Gets the seconds (0-59)

// Error Handling
try {
	//Attempts to execute code that may throw an error
} catch (error) {
	// Handles the error
	console.error(error); // Logs the error to the console
} finally {
	// Executes code after try and catch, regardless of the result
}
// Module Imports and Exports
export const myFunction = () => {/* ... */}; // Exports a function from a module
import { myFunction} from './myModule'; // Imports a function from a module
// JavaScript Class
class Person {
	constructor(name, age) { // Constructor method for initializing an object
		this. name = name;
		this.age = age;
	}
	greet() {
		// Method to greet
		console. log(`Hello, my name is ${this.name}`);
	}
}