Top 50 JavaScript Coding Challenges for Beginners

Top 50 JavaScript Coding Challenges for Beginners

Reverse a String: Write a function that reverses a given string.

• Input: "hello"
• Output: "olleh"

Check for Palindromes: Create a function to check if a string is a palindrome.

• Input: "racecar"
• Output: true

Factorialize a Number: Write a function to find the factorial of a given number.

• Input: 5
• Output: 120

Find the Longest Word in a String: Create a function to find the length of the longest word in a sentence.

• Input: "The quick brown fox jumped over the lazy dog"
• Output: 6

Title Case a Sentence: Write a function that converts a sentence to title case.

• Input: "i am learning javascript"
• Output: "I Am Learning JavaScript"

Find the Largest Numbers in Arrays: Create a function that returns an array containing the largest number from each sub-array.

• Input: [[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39]]
• Output: [5, 27, 39]

Confirm the Ending: Write a function to check if a string ends with a given target string.

• Input: ("Bastian", "n")
• Output: true

Repeat a String Repeat a String: Create a function that repeats a string n times.

• Input: ("abc", 3)
• Output: "abcabcabc"

Truncate a String: Write a function to truncate a string if it is longer than a given maximum string length.

• Input: ("A-tisket a-tasket A green and yellow basket", 8)
• Output: "A-tisket..."

Finders Keepers: Create a function that looks through an array and returns the first element that passes a given test.

• Input: ([1, 3, 5, 8, 9, 10], num => num % 2 === 0)
• Output: 8

Boo Who: Write a function to check if a value is classified as a boolean primitive.

• Input: true
• Output: true

Title Case a Sentence: Write a function to convert the first letter of each word in a sentence to uppercase.

• Input: "I'm a little tea pot"
• Output: "I'm A Little Tea Pot"

Slice and Splice: Create a function that combines two arrays by inserting the second array into the first at a given index.

• Input: ([1, 2, 3], [4, 5], 1)
• Output: [1, 4, 5, 2, 3]

Falsy Bouncer: Write a function that removes all falsy values from an array.

• Input: [7, "ate", "", false, 9]
• Output: [7, "ate", 9]

Where do I Belong: Create a function that returns the lowest index at which a value should be inserted into an array.

• Input: ([40, 60], 50)
• Output: 1

Mutations: Write a function to check if a string contains all the letters of another string.

• Input: ["hello", "hey"]
• Output: false

Chunky Monkey: Create a function that splits an array into groups of the specified size.

• Input: ([1, 2, 3, 4, 5, 6], 2)
• Output: [[1, 2], [3, 4], [5, 6]]

Sum All Numbers in a Range: Write a function that returns the sum of all numbers in a given range.

• Input: [1, 4]
• Output: 10

Seek and Destroy: Create a function that removes all elements from an array that are of the specified values.

• Input: ([1, 2, 3, 1, 2, 3], 2, 3)
• Output: [1, 1]

Wherefore art thou: Write a function to find matching objects in an array.

• Input: [{ first: "Romeo", last: "Montague" }, { first: "Mercutio", last: null }], { last: "Montague" }
• Output: [{ first: "Romeo", last: "Montague" }]

Spinal Tap Case: Create a function that converts a string to spinal case.

• Input: "This Is Spinal Tap"
• Output: "this-is-spinal-tap"

Pig Latin: Write a function to translate a string into Pig Latin.

• Input: "california"
• Output: "aliforniacay"

Search and Replace: Create a function to perform a search and replace on a sentence using the provided arguments.

• Input: ("He is Sleeping on the couch", "Sleeping", "sitting")
• Output: "He is Sitting on the couch"

DNA Pairing: Write a function to pair the DNA strands.

• Input: "GCG"
• Output: [['G', 'C'], ['C', 'G'], ['G', 'C']]

Missing letters: Create a function to find the missing letter in the passed letter range.

• Input: "abce"
• Output: "d"

Sorted Union: Write a function that returns a new array of unique values in the order of the original provided arrays.

• Input: ([1, 3, 2], [5, 2, 1, 4], [2, 1])
• Output: [1, 3, 2, 5, 4]

Convert HTML Entities: Create a function that converts characters such as &, <, >, ", and ' into their corresponding HTML entities.

• Input: "Dolce & Gabbana"
• Output: "Dolce & Gabbana"

Sum All Odd Fibonacci Numbers: Write a function that returns the sum of all odd Fibonacci numbers less than or equal to a given number.

• Input: 10
• Output: 10

Sum All Primes: Create a function to sum all prime numbers up to and including a given number.

• Input: 10
• Output: 17

Smallest Common Multiple: Write a function to find the smallest common multiple of the provided parameters.

• Input: [1, 5]
• Output: 60

Drop it: Create a function that removes elements from an array until the function returns true.

• Input: ([1, 2, 3], n => n >= 3)
• Output: [3]

Steamroller: Write a function to flatten a nested array.

• Input: [1, [2], [3, [[4]]]]
• Output: [1, 2, 3, 4]

Binary Agents: Create a function that translates a binary string into English.

• Input: "01000001 01110010"
• Output: "Ar"

Everything Be True: Write a function to check if all elements in a collection are true.

• Input: [{ name: "John", active: true }, { name: "Doe", active: false }]
• Output: false

Arguments Optional: Create a function that returns the sum of two arguments. If only one argument is provided, return a function that expects one argument and returns the sum.

• Input: 2, 3
• Output: 5

Make a Person: Write a function to create a person object with methods to get and set the person’s name.

• Input: ("John", "Doe")
• Output: { getFirstName: Function, getLastName: Function, setFirstName: Function, setLastName: Function }

Map the Debris: Create a function that returns a new array with the orbital period of each satellite.

• Input: [{ name: "sputnik", avgAlt: 35873.5553 }]
• Output: [{ name: "sputnik", orbitalPeriod: 86400 }]

Pairwise: Write a function that returns the indices of the array elements that add up to the specified target.

• Input: ([1, 4, 2, 3, 0, 5], 7)
• Output: [1, 3]

Implement bubble sort: Create a function that implements the bubble sort algorithm.

• Input: [5, 3, 8, 2, 1, 4]
• Output: [1, 2, 3, 4, 5, 8]

Selection Sort: Write a function to perform selection sort on an array.

• Input: [5, 3, 8, 2, 1, 4]
• Output: [1, 2, 3, 4, 5, 8]

Insert Sort: Create a function that implements the insertion sort algorithm.

• Input: [5, 3, 8, 2, 1, 4]
• Output: [1, 2, 3, 4, 5, 8]

Quick Sort: Write a function to perform quick sort on an array.

• Input: [5, 3, 8, 2, 1, 4]
• Output: [1, 2, 3, 4, 5, 8]

Merge Sort: Create a function that implements the merge sort algorithm.

• Input: [5, 3, 8, 2, 1, 4]
• Output: [1, 2, 3, 4, 5, 8]

Binary Search: Write a function to perform binary search on a sorted array.

• Input: [1, 2, 3, 4, 5, 8], 4
• Output: 3

Recursive Fibonacci: Create a function to calculate the nth Fibonacci number using recursion.

• Input: 10
• Output: 55

Flatten Arrays: Write a function that flattens a nested array.

• Input: [1, [2, [3, [4]], 5]]
• Output: [1, 2, 3, 4, 5]

Sum All Evens: Create a function that sums all even numbers in an array.

• Input: [1, 2, 3, 4, 5, 6]
• Output: 12

Count Vowels: Write a function to count the number of vowels in a string.

• Input: "hello"
• Output: 2

Anagram Checker: Create a function that checks if two strings are anagrams.

• Input: ("listen", "silent")
• Output: true

Palindrome Checker: Write a function to check if a number is a palindrome.

• Input: 121
• Output: true

Top 50 JavaScript Coding Challenges for Beginners