function countLetters(word){
  let counter = {};
  for(let i = 0; i < word.length; i++){
    let position = word.charAt(i)
    if(!counter[position] && position !== " "){
      counter[position] = 1;
    }
    else if(counter[position]){
      counter[position] = counter[position] += 1
      // counter[position] += 1 (this also works)
    }
    console.log(counter)
  }
}

countLetters('hello world')