从jQuery或JS中的json对象中提取数据

Question

我想使用https://raw.github.com/currencybot/open-exchange-rates/master/latest.json提供的货币数据

作为初始测试,我已经创建了一个作为内联对象的简化版本:

var obj = [
{
    "disclaimer": "This data is collected from various providers and provided free of charge for informational purposes only, with no guarantee whatsoever of accuracy, validity, availability, or fitness for any purpose; use at your own risk. Other than that, have fun! More info: http://openexchangerates.org/terms/",
    "license": "Data collected from various providers with public-facing APIs; copyright may apply; not for resale; no warranties given. Full license info: http://openexchangerates.org/license/",
    "timestamp": 1339036116,
    "base": "USD",
    "rates": {
        "EUR": 0.795767,
        "GBP": 0.645895,
        "JPY": 79.324997,
        "USD": 1
    }
}];

我想要做的就是以某种方式查询/ grep /过滤json对象,例如"EUR"作为标准,并让它返回一个名为'rate'的变量,其值为'0.795767'.

我查看了JQuery grep和过滤器函数,但我无法弄清楚如何仅仅隔离对象的'rates'部分然后获得我想要的速率.

Answer 1

var obj = [
{
    "disclaimer": "This data is collected from various providers and provided free of charge for informational purposes only, with no guarantee whatsoever of accuracy, validity, availability, or fitness for any purpose; use at your own risk. Other than that, have fun! More info: http://openexchangerates.org/terms/",
    "license": "Data collected from various providers with public-facing APIs; copyright may apply; not for resale; no warranties given. Full license info: http://openexchangerates.org/license/",
    "timestamp": 1339036116,
    "base": "USD",
    "rates": {
        "EUR": 0.795767,
        "GBP": 0.645895,
        "JPY": 79.324997,
        "USD": 1
    }
}];

obj[0].rates.EUR; // output: 0.795767

要么

obj[0].rates['EUR']; output: //0.795767

DEMO

如果要在另一个变量中隔离速率并使用该变量,请尝试以下操作:

var rates = obj[0].rates;

现在,

rates.EUR;
rates.GBP;

等等.

Answer 2

您还可以使用JSON.parse()Javascript函数将JSON String转换为Javascript JSON对象.

var JSONObject = JSON.parse("{'value1' : 1, 'value2' : 2}");
console.log(JSONObject.value1);  // Prints '1'..