左侧表达式无效

Question

我想弄清楚为什么我编写的底部函数无法正常工作。每当我尝试对其进行测试时，都会收到以下错误：Uncaught ReferenceError: Invalid left-hand side expression in postfix operation。我假设这是因为代码无法将 "x" 字符串识别为与变量 x 相同，一旦它在添加到 x 的值时被去除引号。有人可以帮我巧妙地解决这个问题吗？如果没有，你能建议一些替代方法吗？提前致谢！

var grid = [[null, null, null],
    [null, null, null],
    [null, null, null]];

 function checkWin() {

  vals = ["x", "o"];

  var x = 0;
  var o = 0;

  for (var k = 0; k < vals.length; k++) {

   var value = vals[k];

         for (var i = 0; i < 3; i++) {

             if (grid[i][i] === value) {

              (value.replace(/['"]+/g, '')) ++;

             }

             if (grid[2 - i][i] === value) {

              (value.replace(/['"]+/g, '')) ++;

             }

             for (var j = 0; j < 3; j++) {

                 if (grid[i][j] === value) {

                  (value.replace(/['"]+/g, '')) ++;

                 }

                 if (grid[j][i] === value) {

                  (value.replace(/['"]+/g, '')) ++;

                 }
             }
         }
     }

     if (x === 3) {
      alert("X wins!");
     } else if (o === 3) {
      alert("O wins!");
     }
    }

Answer 1

如何将您的数据放入这样的对象中：

var _ = {
    x : 0,
    o : 0
};

并像这样更改值：

_[value]++;

希望对您有所帮助。

Answer 2

以下使用对象。测试了不同的网格定义

var grid = [
    ["o", "x", "x"],
    ["o", "x", "x"],
    ["o", "", "o"]];

var grid = [
    ["o", "x", ""],
    ["x", "x", "x"],
    ["o", "o", ""]];

var grid = [
    ["x", "x", ""],
    ["o", "x", "o"],
    ["o", "o", "x"]];

var grid = [
    ["x", "x", "o"],
    ["x", "o", "x"],
    ["o", "x", "x"]];

checkWin(grid)      

function checkWin(grid) {

var vals = [{player: "x", value: 0}, {player: "o", value: 0}];

for (var k = 0; k < vals.length; k++) {
    for (var i = 0; i < 3; i++) {
        // check win by row
        vals[k].value = 0;
        // check win by col
        for (var j = 0; j < 3; j++) {
            if (grid[i][j] === vals[k].player) {
                vals[k].value++;
            }
        }
        if (vals[k].value === 3) {
            alert(vals[k].player + " wins by row " + (i+1));
            return vals[k].player;
        }
        // check win by col
        vals[k].value = 0;
        for (var j = 0; j < 3; j++) {
            // check col
            if (grid[j][i] === vals[k].player) {
                vals[k].value++;
                if (vals[k].value === 3) {
                    // break if you want to know what column won by
                    break;
                }
            }
        }
        if (vals[k].value === 3) {
            alert(vals[k].player + " wins by col " + (i+1));
            return vals[k].player;
        }
    }
}
// check win by diag l to r
for (var k = 0; k < vals.length; k++) {
    vals[k].value = 0;
    for (var i = 0; i < 3; i++) {
        if (grid[i][i] === vals[k].player) {
            vals[k].value++;
        }
    }
    if (vals[k].value === 3) {
        alert(vals[k].player + " wins by diag left to right!");
        return vals[k].player;
    }
}   
// check win by diag r to l
for (var k = 0; k < vals.length; k++) {
    vals[k].value = 0;
    for (var i = 0; i < 3; i++) {
        if (grid[i][2-i] === vals[k].player) {
            vals[k].value++;
        }
    }
    if (vals[k].value === 3) {
        alert(vals[k].player + " wins by diag right to left!");
        return vals[k].player;
        }
    }   
}

左侧表达式无效

Invalid left-hand side expression

javascript

referenceerror