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我有以下 JSON 响应。我正在使用 $.getJSON 方法加载 JSON 数据并使用回调函数通过检查它是否为如下数组来进行一些操作。

{
    "r": [{
        "IsDefault": false,
        "re": {
            "Name": "Depo"            
        },
        "Valid": "Oct8, 2013",
        "Clg": [{
            "Name": "james",
            "Rate": 0.05
        }, {
            "Name": "Jack",
            "Rate": 0.55
       }, {
            "Name": "Mcd",
            "Rate": 0.01,
        }],
    },
    {
        "IsDefault": false,
        "re": {
            "Name": "Depo"
        },
        "Valid": "Oct8, 2013",
        "Clg": [{
            "Name": "james",
            "Rate": 0.05
        }, {
            "Name": "Jack",
            "Rate": 0.55
       }, {
            "Name": "Mcd",
            "Rate": 0.01,
        }],
    },
    {
        "IsDefault": false,
        "re": {
            "Name": "Depo"
        },
        "Valid": "Oct8, 2013",
        "Clg": [{
            "Name": "james",
            "Rate": 0.05
        }, {
            "Name": "Jack",
            "Rate": 0.55
       }, {
            "Name": "Mcd",
            "Rate": 0.01,
        }],
    }]
}

我将 loadFromJson1 和 loadFromJson2 函数上的 json 响应作为“输入”作为参数传递，如下所示。

var tablesResult = loadFromJson1(resultstest.r[0].Clg);
    loadFromJson1 = function (input) {
        if (_.isArray(input)) {
        alert("loadFromJson1: Inside array function");
            var collection = new CompeCollection();
            _.each(input, function (modelData) {
                collection.add(loadFromJson1(modelData));
            });
            return collection;
        }
        return new CompeModel({
            compeRates: loadFromJson2(input),
            compName: input.Name
        });
    };

    loadFromJson2 = function (input)
    // here is the problem, the 'input' is not an array object so it is not going to IF condition of the isArray method.
    {
        if (_.isArray(input)) {
            alert("loadFromJson2: Inside array function");
            //alert is not coming here though it is an array
            var rcollect = new rateCollection();
            _.each(input, function (modelData) {
                rcollect.add(modelData);
            });
            return rcollect;
        }
    };

上面的代码我将 loadFromJson1 和 loadFromJson2 函数的 json 响应作为“输入”传递。isArray 仅在 loadFromJson1 函数上为真，并在 if 条件内发出警报，但未进入 loadFromJson2 函数，尽管我传递了相同的参数。

谁能告诉我为什么 loadFromJson2 函数在我传递数组对象时没有在 if 条件下得到警报？

4

1 回答 1

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你不调用loadFromJson2ifinput是一个数组。只有在input不是数组时才调用它。所以_.isArray(input)里面永远不会是真的loadFromJson2。

这是一个演示它的 jsfiddle（打开浏览器的 javascript 控制台以查看日志）。你从你的输入中得到这个输出：

into loadFromJson1 call #1 (index):82
loadFromJson1 #1: it's an Array (index):84
loadFromJson1 #1: Inside array function (index):85
into loadFromJson1 call #2 (index):82
loadFromJson1 #2: not an array (index):93
loadFromJson1 #2: calling loadFromJson2 and returning (index):95
into loadFromJson2 (index):105
loadFromJson2: not an array (index):115
into loadFromJson1 call #3 (index):82
loadFromJson1 #3: not an array (index):93
loadFromJson1 #3: calling loadFromJson2 and returning (index):95
into loadFromJson2 (index):105
loadFromJson2: not an array (index):115
into loadFromJson1 call #4 (index):82
loadFromJson1 #4: not an array (index):93
loadFromJson1 #4: calling loadFromJson2 and returning (index):95
into loadFromJson2 (index):105
loadFromJson2: not an array (index):115
loadFromJson1 #1: returning (index):90

如您所见，对的调用loadFromJson2来自嵌套调用loadFromJson1- 那些得到不是数组的东西的调用。

于 2013-10-20T15:55:06.330 回答