// Long Method

var inputs = "abbcab";

function fn1(letters) {
  let cachePoints = 0;
  let cacheLetter = '';

  for (var i = 0; i < letters.length; i++) {
    const curLetter = letters.charAt(i)
    const compareTo = letters.substring(i+1, letters.length)
    const points = (compareTo.match(new RegExp(curLetter,'g'))|| []).length
    if(cachePoints < points) {
      cachePoints = points
      cacheLetter = curLetter
    }
    document.write(`${points}, ${curLetter} === ${compareTo} <br/>`)
  }
  return cacheLetter;
}

document.write('answer: ' + fn1(inputs))

// Short Method

function fn2(letters){
  let cachePoints = 0;
  let cacheLetter = '';
  for(var i=0; i < letters.length;i++){
    const points = letters.split(letters.charAt(i)).length
    if(cachePoints < points){
      cachePoints = points
      cacheLetter = letters[i]
    }
  }
  return cacheLetter
}

document.write('<br/> answer: ' + fn2(inputs))


// Shorter Method by Mark Rowi

findRepeater = (s) => {
	let higher = 0, letter = '';
	s.split('').forEach(c=>{
		if(s.split(c).length > higher){
       higher = s.split(c).length;
			 letter = c;
		}
	})
	return letter;
}