Question

这是我从websocket收到的json对象。有时，我在数据变量＆amp;中收到一个对象。有时我会收到多个对象。

{"table":"orderBookL2","action":"update","data":
[{"symbol":"XBTU17","id":28499951430,"side":"Sell","size":97140},
{"symbol":"XBTU17","id":28499951510,"side":"Buy","size":48707},
{"symbol":"XBTU17","id":28499951517,"side":"Buy","size":97414},
{"symbol":"XBTU17","id":28499951910,"side":"Buy","size":243535},
{"symbol":"XBTU17","id":28499952128,"side":"Buy","size":487069}]}

Answer 1

假设您在名为“temp”的变量中包含该JSON对象。

然后调用这些将输出：

temp.table //输出：“orderBookL2”
temp.action //输出：“更新”
temp.data // output：[...]数组

现在，如果你想迭代那个数组，只需使用map()函数或使用循环：

for (var i=0; i < temp.length; i++) {
    // do something with temp[i]
    // something like temp[i].symbol is valid!
}

或

temp.map(do_sth(item, index));
// here do_sth() is a function that gets an item of temp array and also 
// index of that item
// or you can even define the function inside the map() function like this:
temp.map(function(item, index){
    // do sth with item or temp[index] which former is recommended
    // sth like item.symbol is valid!
});

有很多方法可以使用.map函数，我建议使用for-loop，这在大多数情况下都非常简单，更容易理解......！

Answer 2

在数组上使用.map函数，你最终会得到类似的东西：

<ul>
    obj.arrayProperty.map( (singleObj, index) => 
        <li key={index}>Symbol: {singleObj.symbol} Id: {singleObj.id} Side: {singleObj.side} Size: {singleObj.size}</li>
    )
</ul>

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map

如何迭代Reactjs中的json对象数组？

2 个答案: