let randomNum = Math.floor(Math.random() * maxNum); 2. Checking If an Object is Empty
function isEmptyObject(obj) { return Object.keys(obj).length === 0; } 3. Creating a Countdown Timer
function countdownTimer(minutes) { let seconds = minutes * 60; let interval = setInterval(() => { if (seconds <= 0) { clearInterval(interval); console.log("Time's up!"); } else { console.log(`${Math.floor(seconds / 60)}:${seconds % 60}`); seconds--; } }, 1000); } 4. Sorting an Array of Objects
function sortByProperty(arr, property) { return arr.sort((a, b) => (a[property] > b[property]) ? 1 : -1); } 5. Removing Duplicates from an Array
let uniqueArr = [...new Set(arr)]; 6. Truncating a String
function truncateString(str, num) { return str.length > num ? str.slice(0, num) + "..." : str; } 7. Converting a String to Title Case
function toTitleCase(str) { return str.replace(/bw/g, txt => txt.toUpperCase()); } 8. Checking If a Value Exists in an Array
let isValueInArray = arr.includes(value); 9. Reversing a String
let reversedStr = str.split("").reverse().join(""); 10. Creating a New Array from an Existing Array
let newArr = oldArr.map(item => item + 1); 11. Debouncing Function Calls
function debounce(func, delay) { let timeout; return function(...args) { clearTimeout(timeout); timeout = setTimeout(() => func.apply(this, args), delay); }; } 12. Throttling Function Calls
function throttle(func, limit) { let lastFunc; let lastRan; return function(...args) { if (!lastRan) { func.apply(this, args); lastRan = Date.now(); } else { clearTimeout(lastFunc); lastFunc = setTimeout(function() { if ((Date.now() - lastRan) >= limit) { func.apply(this, args); lastRan = Date.now(); } }, limit - (Date.now() - lastRan)); } }; } 13. Cloning an Object
const cloneObject = (obj) => ({ ...obj }); 14. Merging Two Objects
const mergeObjects = (obj1, obj2) => ({ ...obj1, ...obj2 }); 15. Checking for Palindrome Strings
function isPalindrome(str) { const cleanedStr = str.replace(/[^A-Za-z0-9]/g, '').toLowerCase(); return cleanedStr === cleanedStr.split('').reverse().join(''); } 16. Counting Occurrences in an Array
const countOccurrences = (arr) => arr.reduce((acc, val) => (acc[val] ? acc[val]++ : acc[val] = 1, acc), {}); 17. Getting the Day of the Year from a Date Object
const dayOfYear = date => Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24); 18. Filtering Unique Values from an Array
const uniqueValues = arr => [...new Set(arr)]; 19. Converting Degrees to Radians
const degreesToRads = deg => (deg * Math.PI) / 180; 20. Delaying Function Execution
const defer = (fn, ...args) => setTimeout(fn, 1, ...args); 21. Flattening a Nested Array
const flattenArray = arr => arr.flat(Infinity); 22. Getting a Random Item from an Array
const randomItem = arr => arr[Math.floor(Math.random() * arr.length)]; 23. Capitalizing the First Letter of a String
const capitalize = str => str.charAt(0).toUpperCase() + str.slice(1); 24. Finding the Max Value in an Array
const maxVal = arr => Math.max(...arr); 25. Finding the Min Value in an Array
const minVal = arr => Math.min(...arr); 26. Shuffling an Array
function shuffleArray(arr) { return arr.sort(() => Math.random() - 0.5); } 27. Removing Falsy Values from an Array
const removeFalsy = arr => arr.filter(Boolean); 28. Generating a Range of Numbers
const range = (start, end) => Array.from({ length: end - start + 1 }, (_, i) => i + start); 29. Checking if Two Arrays are Equal
const arraysEqual = (a, b) => a.length === b.length && a.every((val, i) => val === b[i]); 30. Checking if a Number is Even
const isEven = num => num % 2 === 0; 31. Checking if a Number is Odd
const isOdd = num => num % 2 !== 0; 32. Removing Whitespace from a String
const removeSpaces = str => str.replace(/s+/g, ''); 33. Checking If a String is JSON
function isJSON(str) { try { JSON.parse(str); return true; } catch { return false; } } 34. Deep Cloning an Object
const deepClone = obj => JSON.parse(JSON.stringify(obj)); 35. Checking if a Number is Prime
function isPrime(num) { if (num <= 1) return false; for (let i = 2; i <= Math.sqrt(num); i++) { if (num % i === 0) return false; } return true; } 36. Finding Factorial of a Number
const factorial = num => num <= 1 ? 1 : num * factorial(num - 1); 37. Getting Current Timestamp
const timestamp = Date.now(); 38. Formatting Date as YYYY-MM-DD
const formatDate = date => date.toISOString().split('T')[0]; 39. Generating UUID (Simple)
const uuid = () => 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => { const r = Math.random() * 16 | 0; const v = c === 'x' ? r : (r & 0x3 | 0x8); return v.toString(16); }); 40. Checking if an Object has a Property
const hasProp = (obj, key) => key in obj; 41. Getting Query Parameters from URL
const getQueryParams = url => Object.fromEntries(new URLSearchParams(new URL(url).search)); 42. Escaping HTML Special Characters
const escapeHTML = str => str.replace(/[&<>'"]/g, tag => ({ '&':'&','<':'<','>':'>', "'":''', '"':'"' }[tag])); 43. Unescaping HTML Special Characters
const unescapeHTML = str => str.replace(/&(amp|lt|gt|#39|quot);/g, match => ({ '&':'&','<':'<','>':'>', ''':"'", '"':'"' }[match])); 44. Sleep Function using Promise
const sleep = ms => new Promise(res => setTimeout(res, ms)); 45. Sum of Array Elements
const sumArray = arr => arr.reduce((a, b) => a + b, 0); 46. Average of Numbers in Array
const avgArray = arr => arr.reduce((a, b) => a + b, 0) / arr.length; 47. Finding Intersection of Two Arrays
const intersection = (arr1, arr2) => arr1.filter(x => arr2.includes(x)); 48. Finding Difference of Two Arrays
const difference = (arr1, arr2) => arr1.filter(x => !arr2.includes(x)); 49. Checking if All Elements are Equal
const allEqual = arr => arr.every(val => val === arr[0]); 50. Generating a Random Hex Color
const randomHexColor = () => '#' + Math.floor(Math.random()*16777215).toString(16); Source: DEV Community.
Leave a Reply