循环通过JSON文件 [英] Looping through a JSON file

问题描述

正如标题所示，我正在尝试阅读如下所示的JSON文件：

As the title says I'm trying to read a JSON file that looks like the following:

{
    "response": {
        "current_time": 1490040712, 
        "success": 1, 
        "items": {
            "AK-47 | Black Laminate (Minimal Wear)": {
                "last_updated": 1490025658, 
                "value": 985, 
                "quantity": 124
            }, 
            "AK-47 | Aquamarine Revenge (Field-Tested)": {
                "last_updated": 1490025658, 
                "value": 1775, 
                "quantity": 127
            }, 
            "AK-47 | Black Laminate (Field-Tested)": {
                "last_updated": 1490025658, 
                "value": 890, 
                "quantity": 130
            }, 
            "AK-47 | Aquamarine Revenge (Battle-Scarred)": {
                "last_updated": 1490025658, 
                "value": 1202, 
                "quantity": 70
            }, 
        }
    }
}

现在我要做的是遍历JSON文件并检查是否，例如，AK-47 | Aquamarine Revenge（Battle-Scarred）与给定的字符串相同，然后返回它的价值。我试着在互联网上看看这样做但我没有真正变得更聪明，我尝试了几种方法但他们并没有那么顺利。

Now what I'm trying to do is loop through the JSON file and check if, for example, "AK-47 | Aquamarine Revenge (Battle-Scarred)" is the same as a given string, then return it's value. I tried looking on the internet to get a good look of doing this but I didn't really get much smarter, I tried a few ways but they didn't go so well.

我试过的东西：

    var d, i;
    for (i = 0; i < prices.response.items.length; i++) {
        //d = prices.response.data[i];
        itemPrice = i;
    }

此作品仅供至少返回测试什么，但它根本不起作用，有人可以帮助我吗？

This piece was for testing to just return at least something, but it doesn't work at all, can someone help me?

亲切的问候！

推荐答案

这是检查单个值的方法：

This is how you can check an individual value:

var json =  {"response":
{"success":1,
"current_time":1490040712,
"items":
  {"AK-47 | Aquamarine Revenge (Battle-Scarred)": {"last_updated":1490025658,"quantity":70,"value":1202},
 "AK-47 | Aquamarine Revenge (Factory New)":{"last_updated":1490025658,"quantity":46,"value":3465},
 "AK-47 | Aquamarine Revenge (Field-Tested)":{"last_updated":1490025658,"quantity":127,"value":1775},
 "AK-47 | Aquamarine Revenge (Minimal Wear)":{"last_updated":1490025658,"quantity":92,"value":2427},
 "AK-47 | Aquamarine Revenge (Well-Worn)":{"last_updated":1490025658,"quantity":87,"value":1527},
 "AK-47 | Black Laminate (Battle-Scarred)":{"last_updated":1490025658,"quantity":45,"value":955},
 "AK-47 | Black Laminate (Factory New)":{"last_updated":1490025658,"quantity":11,"value":10152},
 "AK-47 | Black Laminate (Field-Tested)":{"last_updated":1490025658,"quantity":130,"value":890},
 "AK-47 | Black Laminate (Minimal Wear)":{"last_updated":1490025658,"quantity":124,"value":985}}
 }
};

alert(json.response.items["AK-47 | Aquamarine Revenge (Battle-Scarred)"].value);

由于items不是一个列表，而是一个对象，我们不能简单地遍历它。
你只需要像使用
一样迭代它们这就是你得到属性数量的方法：

Since items is not a list, but an object, we cannot simply iterate through it. You just need to iterate through them like using This is how you get the number of properties:

 Object.getOwnPropertyNames(json.response.items).length

参见参考： https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/getOwnPropertyNames

这里有一个代码示例，说明如何遍历链接上的键和值。

Here there is a code example of how to iterate through keys and values at the link.

 Object.getOwnPropertyNames(json.response.items).forEach(
   function (val, idx, array) {
    console.log(val + ' -> ' + obj[val]);
   }
 );

这篇关于循环通过JSON文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！