countVowels.js

// taking in a string
// find out how many vowels are in that string
// return # of vowels that we get from that string

// the word "why" would return 0 vowels
// the word hello should return two vowels
// input the string "Tuesday" : 3

// return the sum of all the vowels contained in the string

// split method turns each character from a string into an array
// loop over the string characters array
// crosss reference vowels(a, e, i, o, u) to the string input using a loop on array || regex || object
// comparing each character to the vowels
// Increment if they match
// return the count


function findVowels(str) {
    // With arrays
    let strArray = str.toLowerCase().split('');
    let vowels = ['a', 'e', 'i', 'o', 'u'];
    let vowelCount = 0;
  
    for (let i = 0; i < strArray.length; i++) {
      for (let j = 0; j < vowels.length; j++) {
        if (strArray[i] === vowels[j]) {
          vowelCount++;
        }
      }
    }
    return vowelCount;
}
  
  
// test if the character (strArray[i]) is in the vowels regex
function findVowels(str) {
  // With Regular Expression test
  let strArray = str.toLowerCase().split('');
  let vowels = /[aeiou]/;
  let vowelCount = 0;

  for (let i = 0; i < strArray.length; i++) {
    if (vowels.test(strArray[i])) {
     vowelCount++;
    }
  }
  return vowelCount;
}
  
// test if the character (strArray[i]) is in the vowels object
function findVowels(str) {
  // With Regular Expression test
  let strArray = str.toLowerCase().split('');
  let vowels = {
    a: '', //better to use truthy instead of falsy like having a: true instead of ''
    e: '',
    i: '',
    o: '',
    u: ''
  };
  let vowelCount = 0;

  for (let i = 0; i < strArray.length; i++) {
    if (vowels[strArray[i]]) {
     vowelCount++;
    }
  }
  return vowelCount;
}
  
  
console.log(findVowels('why'));
console.log(findVowels('how many vowels are in that string'));

//USING INCLUDES
function findVowel(str) {
  let vowel = 'aeiouAEIOU';
  let count = 0
  for (let char of str) {
    if (vowel.includes(char)) {
      count++
    }
  }
  return count;
}

console.log(findVowel('daniel') )

//TO LOWERCASE()
function findVowels(str) {
  let vowel = 'aeiou';
  let count = 0;

  for (let char of str) {
    if (vowel.includes(char.toLowerCase())) {
      count++;
    }
  }
  return count;
}


//USING INCLUDES WITH REDUCE
function findVowels(str) {
  const vowels = 'aeiou';
  return str
    .split('')
    .reduce((count, char) => vowels.includes(char) ? count + 1 : count, 0);
}


//REGEX (MATCH)
const findVowels = str => (str.match(/[aeiou]/g) || []).length;