問題描述

如何修復此井字遊戲的未捕獲參考錯誤 (How do I fix an uncaught reference error for this TicTacToe)

我正在做一個 HTML、CSS、JSS tictactoe 項目，我遇到了一個錯誤，當我嘗試使用時，控制台功能區/部分（右鍵單擊並轉到瀏覽器中的“檢查”時）顯示以下內容我的文本編輯器中的 console.log：

“未捕獲的 ReferenceError：topLeft 未定義” if (topLeft && topLeft === topMiddle && topLeft === topRight) {

我的代碼：

             // HTML Elements
const statusDiv = document.querySelector('.status');
const resetDiv = document.querySelector('.reset');
const cellDivs = document.querySelectorAll('.game‑cell');
//NEW querySelecterAll <= will grab every occurrence put in ('') 
//Grabbing statusDiv to manipulate it (change when it'll x or o's turn)

            //Game Variables
let gameIsLive = true; 
//statement would be false if someone won/ game ended 
let xIsNext = true; 
//meaning if it's T = x's turn, if it's F = O's turn

           // Functions
const checkGameStatus = () => {
const topLeft = cellDivs[0].classList[2];
const topMiddle = cellDivs[1].classList[2];
const topRight = cellDivs[2].classList[2];
const middleLeft = cellDivs[3].classList[2];
const middleMiddle = cellDivs[4].classList[2];
const middleRight = cellDivs[5].classList[2];
const bottomLeft = cellDivs[6].classList[2];
const bottomMiddle = cellDivs[7].classList[2];
const bottomRight = cellDivs[8].classList[2];
}

           // Check Winner
if (topLeft && topLeft === topMiddle && topLeft === topRight) { 
console.log(topLeft);
}

我做的代碼好像和視頻一樣，所以我不確定為什麼會收到這個錯誤。

參考

• GitHub

教程中的人有自己的GitHub，代碼在此處輸入鏈接描述

我之前發布了一個類似的問題，這是我第一次解決問題。有點擔心它可能會再次關閉，所以請讓我知道我做錯了問題的哪一部分。

• Youtube

這將是我目前的流程 在此處輸入鏈接描述

我之前發布了一個類似的問題，這是我第一次解決問題。有點擔心它可能會再次關閉，所以請讓我知道我做錯了問題的哪一部分。

參考解法

方法 1:

Your issue is with block scoping. You're declaring your variables inside this block:

const checkGameStatus = () => {
  const topLeft = cellDivs[0].classList[2];
  [...]
}

But then you're trying to access the variables outside the block, where they don't exist.

Instead, initialize the variables outside the block, and then assign the values:

let topLeft;

const checkGameStatus = () => {
  topLeft = cellDivs[0].classList[2];
  [...]
}

checkGameStatus()

if (topLeft && topLeft === topMiddle && topLeft === topRight) { 
  console.log(topLeft);
}

(by KO‑d14、selfagency)

參考文件

1. How do I fix an uncaught reference error for this TicTacToe (CC BY‑SA 2.5/3.0/4.0)