exes_and_ohs.js

// Exes and Ohs 
// Solution 1 
function XO(str) {
  return str.toLowerCase().charAt('x').length === str.toLowerCase().charAt('o').length;
}




// Or... 
function XO(str) {
  // Initialize storage arrays (This works, but uses O(N) extra memory) 
  let x = [];
  let o = [];
  
  // Iterate over every character in the string
  for (let i = 0; i < str.length; i++) {
    // Check for 'x', case-insensitive
    if (str[i].toLowerCase() === "x") {
      x.push(str[i]); // Store the character
    } 
    // Check for 'o', case-insensitive
    else if (str[i].toLowerCase() === "o") {
      o.push(str[i]); // Store the character
    }
  }
  
  // Compare the number of items collected in each array
  if (x.length === o.length) {
    return true;
  } else {
    return false;
  }
}






// Or...
function XO(str) {
  // Single variable to track the "balance" between Xs and Os
  let balance = 0;

  for (let char of str.toLowerCase()) {
    if (char === 'x') balance++;
    if (char === 'o') balance--;
  }

  // If balance returns to 0, amounts were equal.
  return balance === 0;
}