Discussion on: Daily Challenge #44 - Mexican Wave

function charactersIndexes(string) {
  return string.split("").reduce(function(indexes, character, index) {
    if (!/\s/.test(character)) {
      indexes.push(index);
    }

    return indexes
  }, []);
}

function upperCaseAt(index, string) {
  return string.split("").map(function(character, position) {
    if (position === index) {
      return character.toUpperCase();
    }

    return character;
  }).join("");
}

function wave(input) {
  return charactersIndexes(input).map((index) => upperCaseAt(index, input));
}

console.log(wave("hello"));
// [ 'Hello', 'hEllo', 'heLlo', 'helLo', 'hellO' ]

console.log(wave("h e l l o"));
// [ 'H e l l o', 'h E l l o', 'h e L l o', 'h e l L o', 'h e l l O' ]