CodeWars

toWeirdCaes

let p =
  "The quick brown fox jumps over the lazy dog. If the dog reacted, was it really lazy?";

function toWeirdCase(InputString) {
  return InputString.split("")
    .filter(l => l.match(/[a-zA-Z]/))
    .map((l, i) => (i % 2 ? l.toLowerCase() : l.toUpperCase()))
    .join("");
}

console.log(toWeirdCase(p));