JavaScript_CheatSheet.md

JavaScript:

# Declare a variable using let or const.
    let myVariable = 'hello';
    const myConstant = 42;

# Log a message to the console.
    console.log('Hello, world!');

# Alert a message to the user.
    alert('Hello, user!');

# Prompt the user for input.
    let userInput = prompt('What is your name?');

# Declare a function.
    function myFunction(arg1, arg2) {
        Function body goes here.
    }

# Call a function.
    myFunction(value1, value2);

# Declare an object.
    let myObject = {
        key1: 'value1',
        key2: 'value2',
        key3: 'value3',
    };

# Access an object's property.
    myObject.key1;

# Declare an array.
    let myArray = [1, 2, 3, 4];

# Access an array's element.
    myArray[0];

# Declare a for loop.
    for (let i = 0; i < myArray.length; i++) {
        Loop body goes here.
    }

# Declare a while loop.
    while (condition) {
        Loop body goes here.
    }

# Declare an if statement.
    if (condition) {
        Code to execute if condition is true.
    }

# Declare an if-else statement.
    if (condition) {
        Code to execute if condition is true.
    } else {
        Code to execute if condition is false.
    }

# Declare a switch statement.
    switch (expression) {
        case value1:
            Code to execute if expression equals value1.
            break;
        case value2:
            Code to execute if expression equals value2.
            break;
        default:
            Code to execute if expression doesn't match any case.
    }

# Declare a try-catch block.
    try {
        Code that might throw an error.
    } catch (error) {
        Code to handle the error.
    }

# Declare a timeout function.
    setTimeout(function() {
        Code to execute after a delay.
    }, delay);

# Declare an interval function.
    setInterval(function() {
        Code to execute repeatedly at an interval.
    }, interval);

# Declare a callback function.
    function myFunction(callback) {
        Code to execute before the callback.
        callback();
        Code to execute after the callback.
    }

# Declare a promise.
    let myPromise = new Promise(function(resolve, reject) {
        Code that might resolve or reject the promise.
    });

# Use the then method of a promise.
    myPromise.then(function(result) {
        Code to execute if the promise resolves successfully.
    }).catch(function(error) {
        Code to execute if the promise is rejected.
    });

# Declare a class.
    class MyClass {
        constructor(arg1, arg2) {
            Constructor code goes here.
        }
        myMethod(arg1, arg2) {
            Method body goes here.
        }
    }

# Declare a module.
    export function myFunction(arg1, arg2) {
        Code to export goes here.
    }

# Import a module
    import { myFunction } from './my-module.js';