计算JSON字符串中元素的数量

Question

我有一个JSON字符串，代表一个包含一行数据的数据表。以下是该表：

"MyData":[
    {
        "FirstName":"John",
        "LastName":"Doe",
        "ID":1234,
        "QCR3m":null,
        "FR3m":null,
        "ERI3m":null,
        "QCR6m":null,
        "FR6m":null,
        "ERI6m":null,
        "QCR1y":90.05,
        "FR1y":null,
        "ERI1y":93.55,
        "QCR3y":93.51,
        "FR3y":95.86,
        "ERI3y":94.0,
        "QCR5y":93.25,
        "FR5y":95.86,
        "ERI5y":94.0
    }
]

我想要计算MyData表格中的列数。在这种情况下，列数为18。这个能在javascript中实现吗？

- joelforsyth

Answer 1

使用Object.keys和length属性。

var obj = {
        "FirstName":"John",
        "LastName":"Doe",
        "ID":1234,
        "QCR3m":null,
        "FR3m":null,
        "ERI3m":null,
        "QCR6m":null,
        "FR6m":null,
        "ERI6m":null,
        "QCR1y":90.05,
        "FR1y":null,
        "ERI1y":93.55,
        "QCR3y":93.51,
        "FR3y":95.86,
        "ERI3y":94.0,
        "QCR5y":93.25,
        "FR5y":95.86,
        "ERI5y":94.0
    };

console.log(Object.keys(obj).length);

- AmmarCSE