Javascript索引对象内的数组

Question

我错过了一个简单的语法规则，所以也许你可以向我指出。

我有一个对象定义如下......

var board = {
  //this data structure was heavily discussed with Lydia Brothers. its current form is due to her help
  state: {
    flipped: true,
    ballWasDroppedLastMove: false,
    topPlace: 0,
    bottomPlace: 0,
    top:    [[1,2,3,4,5,6],[7,8,9,10,11,99],[12,13,14,15,99,99],[16,17,18,99,99,99],[19,20,99,99,99,99],[21,99,99,99,99,99]],
    bottom: [[0,0,0,0,0,0],[0,0,0,0,0,99],  [0,0,0,0,99,99],    [0,0,0,99,99,99],   [0,0,99,99,99,99],  [0,99,99,99,99,99]],
  }, ...

我对这个对象做了一些操作 - 特别是我对board.state.top感兴趣。

当我将board.state.top打印到控制台时，我得到如下图所示的内容......

我想访问值12,11,0,0,99,99。

我从其他语言的经验告诉我，我应该做这样的事情......

for (i=0; i<6; i++){
  console.log(pboard.state.top[i])
}

......而这正是我得到上述图片的方式。我尝试过类似board.state.top[i][j]（添加额外维度）的内容，但会打印值0,0,0,0,99,99

如何访问这些元素？

如下所述，我尝试了以下（无论如何）......

var i;
var j;
for (i=0; i<6; i++){
  row = pboard.state.top[i];
  row.forEach(element => {console.log(element);});
  // for (j=0; j<6; j++){
  //   console.log(top[j])
  // }
}

Answer 1

为了简化操作，请按系统顺序进行。

首先从属性array检索board.state.top并将其存储在变量中。

然后使用forEach API迭代元素。

示例：

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var board = {
  //this data structure was heavily discussed with Lydia Brothers. its current form is due to her help
  state: {
    flipped: true,
    ballWasDroppedLastMove: false,
    topPlace: 0,
    bottomPlace: 0,
    top: [[1, 2, 3, 4, 5, 6], [7, 8, 9, 10, 11, 99], [12, 13, 14, 15, 99, 99], [16, 17, 18, 99, 99, 99], [19, 20, 99, 99, 99, 99], [21, 99, 99, 99, 99, 99]],
    bottom: [[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 99], [0, 0, 0, 0, 99, 99], [0, 0, 0, 99, 99, 99], [0, 0, 99, 99, 99, 99], [0, 99, 99, 99, 99, 99]],
  }
}

var that_row = board.state.top[2];
that_row.forEach(element => { console.log(element); });

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Answer 2

试试这个。它应该工作。您需要达到该值，然后逐个获得所需的值。像这样的东西

state.top.forEach(function(innerItem){
  innerItem.forEach(function(item){
      console.info(item);
    })
})

希望它有所帮助。

快乐学习：）

Answer 3

以下代码段将在pos属性中打印其数组的每个值：

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var board = {
  //this data structure was heavily discussed with Lydia Brothers. its current form is due to her help
  state: {
    flipped: true,
    ballWasDroppedLastMove: false,
    topPlace: 0,
    bottomPlace: 0,
    top: [[1, 2, 3, 4, 5, 6], [7, 8, 9, 10, 11, 99], [12, 13, 14, 15, 99, 99], [16, 17, 18, 99, 99, 99], [19, 20, 99, 99, 99, 99], [21, 99, 99, 99, 99, 99]],
    bottom: [[0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 99], [0, 0, 0, 0, 99, 99], [0, 0, 0, 99, 99, 99], [0, 0, 99, 99, 99, 99], [0, 99, 99, 99, 99, 99]],
  }
}

board.state.top.forEach(function(pos, topIndex) {
    pos.forEach(function(v, i) {
        console.log('From top index', topIndex, 'value in position', i, v);
    });
});

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