1// Traditional Function
2function multiplyBy2(input) {
3  return input * 2;
4}

1// Remove the word "function" and place arrow between the argument and opening body bracket
2const multiplyBy2 = (input) => {
3  return input * 2;
4};

1// Remove the body brackets and word "return" -- the return is implied
2const multiplyBy2 = (input) => input * 2;

1// Remove the argument parenthesis
2const multiplyBy2 = (input) => input * 2;

1const output = multiplayBy2(3); // 6