Question

我知道我必须遗漏一些非常基本的东西，但我能用一双新鲜的眼睛来做。

我有一个对象数组（参见代码）。

我正在尝试读取每个对象的属性variants的值。

我尝试过很多种组合。例如，如果我object.variants或object[0].variants，则结果为undefined。

有人可以告诉我为什么好吗？

更新：我需要循环遍历数组中的对象，并为每个对象检查variants属性。如果它不是null，那么抓住它的值并记录它们。

   [
    {
        "type": "text",
        "complete": true,
        "startPoint": {
            "x": 233.84,
            "y": 82.13
        },
        "endPoint": {
            "x": 461.27,
            "y": 79.74
        },
        "text": "xvxvs xsvx vx",
        "variants": [
            "xvxvs",
            "xsvx",
            "vx"
        ]
    },
    {
        "type": "text",
        "complete": true,
        "startPoint": {
            "x": 515.39,
            "y": 120.84
        },
        "endPoint": {
            "x": 803.67,
            "y": 111.31
        },
        "text": "casdc adcasdcasc",
        "variants": [
            "casdc",
            "adcasdcasc"
        ]
    }
]

Answer 1

假设您有一个包含此内容的javascript变量：

var obj = 
    [
        {
            "type": "text",
            "complete": true,
            "startPoint": {
                "x": 233.84,
                "y": 82.13
            },
            "endPoint": {
                "x": 461.27,
                "y": 79.74
            },
            "text": "xvxvs xsvx vx",
            "variants": [
                "xvxvs",
                "xsvx",
                "vx"
            ]
        },
        {
            "type": "text",
            "complete": true,
            "startPoint": {
                "x": 515.39,
                "y": 120.84
            },
            "endPoint": {
                "x": 803.67,
                "y": 111.31
            },
            "text": "casdc adcasdcasc",
            "variants": [
                "casdc",
                "adcasdcasc"
            ]
        }
    ];

然后您可以访问变体内容，如下所示：

alert(obj[0].variants);

以及它的工作演示：http://jsfiddle.net/66o8h5de/

所以基本上obj是一个数组，obj[0]表示此数组的第一个元素，obj[0].variants是此数组第一个元素的variants属性。当然，根据您的需要，您可能希望遍历此obj数组的元素，在这种情况下，您可以使用for循环：

for(var i = 0; i < obj.length; i++) {
    var element = obj[i];
    alert(element.variants);
}

Answer 2

您可以使用此jsfiddle

之类的forEach()功能

objects.forEach(function(element, index, array) {
   console.log(element.variants); 
});

Answer 3

您有一个对象数组，其中每个对象包含更多数组的键。使用forEach迭代对象然后再为变量数组迭代的方法：

＆＃13;

var array = [{"type":"text","complete":true,"startPoint":{"x":233.84,"y":82.13},"endPoint":{"x":461.27,"y":79.74},"text":"xvxvs xsvx vx","variants":["xvxvs","xsvx","vx"]},{"type":"text","complete":true,"startPoint":{"x":515.39,"y":120.84},"endPoint":{"x":803.67,"y":111.31},"text":"casdc adcasdcasc","variants":["casdc","adcasdcasc"]}]

array.forEach(function(element) {
  variantArray = element.variants;
  variantArray.forEach(function(variant) {
    document.write(variant + "<br>");  
  });
  document.write("<br>");
});

＆＃13;

Answer 4

var arr =  [
    {
        "type": "text",
        "complete": true,
        "startPoint": {
            "x": 233.84,
            "y": 82.13
        },
        "endPoint": {
            "x": 461.27,
            "y": 79.74
        },
        "text": "xvxvs xsvx vx",
        "variants": [
            "xvxvs",
            "xsvx",
            "vx"
        ]
    },
    {
        "type": "text",
        "complete": true,
        "startPoint": {
            "x": 515.39,
            "y": 120.84
        },
        "endPoint": {
            "x": 803.67,
            "y": 111.31
        },
        "text": "casdc adcasdcasc",
        "variants": [
            "casdc",
            "adcasdcasc"
        ]
    }
];


var len = arr.length;

for(var i=0;i<len;i++){
  var obj = arr[i];
  console.log(obj["variants"]);
}

Answer 5

确保将其分配给变量

＆＃13;

var arr =    [
    {
        "type": "text",
        "complete": true,
        "startPoint": {
            "x": 233.84,
            "y": 82.13
        },
        "endPoint": {
            "x": 461.27,
            "y": 79.74
        },
        "text": "xvxvs xsvx vx",
        "variants": [
            "xvxvs",
            "xsvx",
            "vx"
        ]
    },
    {
        "type": "text",
        "complete": true,
        "startPoint": {
            "x": 515.39,
            "y": 120.84
        },
        "endPoint": {
            "x": 803.67,
            "y": 111.31
        },
        "text": "casdc adcasdcasc",
        "variants": [
            "casdc",
            "adcasdcasc"
        ]
    }
]
console.log(arr[0].variants)

＆＃13;

Answer 6

还有一个： - ）

＆＃13;

var data =   
  [
    {
        "type": "text",
        "complete": true,
        "startPoint": {
            "x": 233.84,
            "y": 82.13
        },
        "endPoint": {
            "x": 461.27,
            "y": 79.74
        },
        "text": "xvxvs xsvx vx",
        "variants": [
            "xvxvs",
            "xsvx",
            "vx"
        ]
    },
    {
        "type": "text",
        "complete": true,
        "startPoint": {
            "x": 515.39,
            "y": 120.84
        },
        "endPoint": {
            "x": 803.67,
            "y": 111.31
        },
        "text": "casdc adcasdcasc",
        "variants": [
            "casdc",
            "adcasdcasc"
        ]
    }
]
;

for ( var i in data ) {
  $('pre').append( data[i].variants + "\n");
}
And one more ;-)

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<pre></pre>

＆＃13;

如何访问对象数组的属性

6 个答案: