#2 How to replace for with .reduce?

Question

JavaScript

There is this code:

const rX = 'xX';
const rO = 'oO';
let rCountX = 0;
let rCountO = 0;

for (let i = 0; i < str.length; i++) {
  if (rX.includes(str[i])) {
    rCountX++;
  } else if (rO.includes(str[i])) {
    rCountO++;
  }
}
rCountX === rCountO ? true : false;

I want to shorten it by replacing For with .reduce,
but I start to slow down at the moment,
but where should I place rCountX and rCountO in the redux?

Answer 1

const rCount = Array.prototype.reduce.call(str, (acc, letter) => {
    if (rX.includes(letter)) {
      acc.X++;
    } else if (rO.includes(letter)) {
      acc.O++;
    }
    return acc;
  }, { X: 0, O: 0 });

But, since this is clearly tic-tac-toe, it can be implemented much more beautifully.

const rCount = Array.prototype.reduce.call(str.toLowerCase(), (acc, letter) => {
    switch(letter) {
      case 'x':
        acc.X++;
        break;
      case 'o':
        acc.O++;
        break;
    }
    return acc;
  }, { X: 0, O: 0 });

Answer 2

https://developer.mozilla.org/en/docs/Web/JavaScri... is a function for working with arrays, while rX, rO are strings. Convert them to arrays and use reduce if you like.