vowel-doubler

vowel-doubler.js

// Inputs: Array of 1 character strings
// Outputs: The same array of character strings with all the vowels 'doubled'
// Constraints: Do not manipulate strings nor create data structures or a new array. 
// Edge cases: None

// Pseudocode implementation:
  // Create an object that one can compare each character in the array to, indicating whether a char is a vowel.
  // For each index in the array, starting at the 0 index up to arr.length - 1
    // Create a current character variable that will represent the string at a given index in the array
    // If the char is a vowel
      // Splice the array at the current index
      // Add the current character
      // Increment the index by 1 so that one will not run into the same character again on the next iteration of this loop
  
  // Return the original array

const vowelDoubler = (arr) => {
  const vowels = {'a': true, 'e': true, 'i': true, 'o': true, 'u': true};
  
  for (let i = 0; i < arr.length; i++) {
    let char = arr[i];
    if (vowels[char]) {
      arr.splice(i, 0, char);
      i++;
    }
  }
  
  return arr;
}