Code Academy 10 JavaScript code challenges for beginners

index.js

// Challenges
// - Try to make the solution to this problem as efficiently as possible.
// - Try to make optimized output


// Print all even numbers from 0 – 10
function printEvenNumbers(start = 0, end) {
  for (let i = start; i <= end; i++) {
    if (i % 2 === 0) console.log(i);
  }
}
printEvenNumbers(0, 10);

// Print a table containing multiplication tables from 1 to 10
function printTable(start = 1, end) {
  for (let i = start; i <= end; i++) {
    for (let j = 1; j <= 10; j++) {
      console.log(`${i} x ${j} = ${i * j}`);
    }
  }
}
printTable(1, 10);



// The function should include the input in kilometers and return the answer in miles.
function convertKilometersToMiles(kilometers) {
  return kilometers * 0.621371;
}



// Calculate the sum of numbers within an array
function sumOfNumbers(numbers) {
  return numbers.reduce((acc, curr) => acc + curr);
}
sumOfNumbers([1, 2, 3, 4, 5]);



// Create a function that reverses an array
function reverseArray(array) {
  return array.reverse();
}
reverseArray([1, 2, 3, 4, 5]);



// Sort an array from lowest to highest
function sortArray(array) {
  return array.sort((a, b) => a - b);
}
sortArray([1, 2, 3, 4, 5]);



// Create a function that filters out negative numbers
function filterNegativeNumbers(numbers) {
  return numbers.filter((number) => number >= 0);
}
filterNegativeNumbers([1, 2, 3, 4, 5, -1, -2, -3, -4, -5]);



// Remove the spaces found in a string
function removeSpaces(string) {
  return string.replace(/\s/g, '');
}
removeSpaces('Hello World');



//Return a Boolean if a number is divisible by 10
function isDivisibleBy10(number) {
  return number % 10 === 0;
}
isDivisibleBy10(10);



// Return the number of vowels in a string
function countVowels(string) {
  return string.match(/[aeiou]/gi).length;
}
countVowels('Hello World');