Challenge-39.js

// DESCRIPTION:
// Given two strings comprised of + and -, return a new string which shows how the two strings interact in the following way:

// When positives and positives interact, they remain positive.
// When negatives and negatives interact, they remain negative.
// But when negatives and positives interact, they become neutral, and are shown as the number 0.
// Worked Example
// ("+-+", "+--") ➞ "+-0"
// # Compare the first characters of each string, then the next in turn.
// # "+" against a "+" returns another "+".
// # "-" against a "-" returns another "-".
// # "+" against a "-" returns "0".
// # Return the string of characters.
// Examples
// ("--++--", "++--++") ➞ "000000"

// ("-+-+-+", "-+-+-+") ➞ "-+-+-+"

// ("-++-", "-+-+") ➞ "-+00"

//solutions

function neutralise(s1, s2) {
  let res = "";
  for (let i = 0; i < s1.length; i++) {
    res += s1[i] !== s2[i] ? "0" : s1[i];
  }
  return res;
}

neutralise("-+-+-+", "-+-+-+");