从 JSON 嵌套哈希中提取特定字段 [英] Extract specific field from JSON nested hashes

问题描述

我正在考虑编写一个 Web 应用程序，该应用程序会抓取 API 并以 JSON 形式返回此信息.

I am thinking of writing a web application that crawls an API and returns this information in JSON form.

但是，我只需要一个数字，然后是当前价格(在此示例中为227").我如何在 Ruby 中访问它?我不知道从哪里开始.我从来没有处理过这样的文本.

However, I am only after one number, then current price (in this sample, "227"). How can I access that in Ruby? I have no clue where to begin. I've never dealt with text like this.

为了讨论，假设我将此输出保存到实例变量 @information

For discussion's sake, suppose I save this output into instance variable @information

{
    "item": {
        "icon": "http://services.runescape.com/m=itemdb_rs/4332_obj_sprite.gif?id=4798",
        "icon_large": "http://services.runescape.com/m=itemdb_rs/4332_obj_big.gif?id=4798",
        "id": 4798,
        "type": "Ammo",
        "typeIcon": "http://www.runescape.com/img/categories/Ammo",
        "name": "Adamant brutal",
        "description": "Blunt adamantite arrow...ouch",
        "current": {
            "trend": "neutral",
            "price": 227
        },
        "today": {
            "trend": "neutral",
            "price": 0
        },
        "day30": {
            "trend": "positive",
            "change": "+1.0%"
        },
        "day90": {
            "trend": "positive",
            "change": "+1.0%"
        },
        "day180": {
            "trend": "positive",
            "change": "+2.0%"
        },
        "members": "true"
    }
}

推荐答案

首先关注这个帖子把这个JSON解析成Hash在 Ruby 中解析 JSON 字符串

First follow this post to parse this JSON in to Hash Parsing a JSON string in Ruby

说解析的哈希名称是 my_hash 那么下面应该给你价格

say the parsed hash name is my_hash then the following should give you price

my_hash['item']['current']['price']

正如你所说，你想把它保存在@information

As you said you want to save it in @information

@information = my_hash['item']['current']['price']

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