5 beginner level JavaScript challenges to boost your skills

1. Write a function that takes in a string and returns the string with all vowels removed. For example, the input “javascript” should return “jvscrpt”.

To remove all vowels from a string, you can use the replace method to search for and replace any vowels in the string with an empty string. You can use a regular expression to match any vowels, using the [aeiouAEIOU] pattern. For example:


function removeVowels(str) {
  return str.replace(/[aeiouAEIOU]/g, '');
}

2. Write a function that takes in an array of numbers and returns the sum of all the numbers in the array. For example, the input [1, 2, 3] should return 6.

To find the sum of all the numbers in an array, you can use a for loop to iterate through the array and add each number to a running total. For example


function sumArray(numbers) {
  let total = 0;
  for (let i = 0; i < numbers.length; i++) {
    total += numbers[i];
  }
  return total;
}

3. Write a function that takes in a number and returns “Fizz” if the number is divisible by 3, “Buzz” if it is divisible by 5, and “FizzBuzz” if it is divisible by both 3 and 5. For example, the input 15 should return “FizzBuzz”.

To return “Fizz”, “Buzz”, or “FizzBuzz” based on a number’s divisibility, you can use the % operator to check for the remainder when the number is divided by 3 or 5. If the number is divisible by 3, you can return “Fizz”. If it’s divisible by 5, you can return “Buzz”. If it’s divisible by both 3 and 5, you can return “FizzBuzz”. For example:


function fizzBuzz(num) {
  if (num % 3 === 0 && num % 5 === 0) {
    return "FizzBuzz";
  } else if (num % 3 === 0) {
    return "Fizz";
  } else if (num % 5 === 0) {
    return "Buzz";
  }
}

4. Write a function that takes in a string and returns the string in reverse. For example, the input “javascript” should return “tpircsavaj”

To reverse a string, you can use the split, reverse, and join methods to first split the string into an array of characters, then reverse the array, and finally join the reversed array back into a string. For example:


function reverseString(str) {
  return str.split('').reverse().join('');
}

5. Write a function that takes in an array of strings and returns an array with only the strings that have a length of 4 or more. For example, the input [“cat”, “dog”, “elephant”] should return [“elephant”].

To filter an array of strings to only include strings of a certain length, you can use the filter method and a callback function that checks the length of each string. The filter method will return a new array containing only the elements that return true when passed to the callback function. For example:


function filterLongStrings(strings) {
  return strings.filter(str => str.length >= 4);
}

To conclude, practicing coding challenges is a great way for beginners to improve their JavaScript skills and gain confidence in their ability to solve problems. The five challenges listed above cover a range of concepts and techniques that are important to understand as a beginner, including string manipulation, array iteration, conditional statements, and function parameters. By working through these challenges, you can gain a solid foundation in JavaScript and continue to build on your skills as you progress in your coding journey.