Javascript :: defining constants w/ default params #js

DefiningConstantsWDefaultParams1.js

const exponentiate = (base, power) => {
  let exponentiatedValue = 1;
  
  for (i = 1; i <= power; ++i) {
    exponentiatedValue *= base;
  }
  return exponentiatedValue;
}

// can do the same thing with:
const exponentiate = (base, power) => base ** power;


// other example

// Default Parameters
// A way to stipulate what the value of an argument is should one not be passed into function

const mySlice = (source, startIdx = 0, endIdx = source.length) => {
    let slicedString = '';
    
    for (let i = startIdx; i < endIdx; ++i) {
        const curChar = source[i];
        
        slicedString += curChar;
    }
    return slicedString
}

const myIndexOf = (source, searchValue, startIdx = 0) => {
  for (let i = startIdx; i <= source.length - searchValue.length; i++) {
    let substring = source.slice(i, i+searchValue.length);
    if (substring === searchValue) {
      return i;
    } 
  } return -1;
}

// Most vowels word return from a sentence. Example:
const mostVowels = (aStr) => {
    const wordsArray = aStr
        .split('.')
        .join('')
        .split(',')
        .join('')
        .split(' ');
    
    const VOWELS = 'aeiouAEIOU';
    
    let maxVowelCount = 0;
    let maxWord = '';
    
    for (let i = 0; i < wordsArray.length; ++i) {
        const currentWord = wordsArray[i];
        
        let currentVowelCount = 0;
        
        // This loops job is to count vowels per word, when its done looping we have finished for this word.
        for (var j=0; j < currentWord.length; ++j) {
            const currentLetter = currentWord[j];
            
            // We found a vowel!
            if (VOWELS.indexOf(currentLetter) !== -1) {
                ++currentVowelCount;
            }
        }
        // Were done counting.
        if (currentVowelCount > maxVowelCount) {
            maxVowelCount = currentVowelCount;
            maxWord = currentWord;
        }
    }
    return maxWord;
    // This outer loop says we went through each word, updating the maxWord if it had the most vowels.
}