Jquery 如何检查JSON对象中的第一个值？

我从一个API获得返回的json，需要检查第一个对象（没有键/值）以获得jQueryAjax成功函数。通常情况下，返回类似JSON的

{"type":"Return","FirstName":"test","LastName":"test"}

我可以这样检查

success: function(data){
        if(data.type == "Return"){
            //do stuff  
        } else {
            //failed
        }
}

我如何执行相同类型的检查，以查看像这样的对象的值是“tax”还是“error”

{"tax":{"order_total_amount":1099.0,"shipping":0.0}}

success: function(data){
    if(data[0] == "tax"){
        //do stuff
    } else {
        //failed
    }
}

不起作用。我做错了什么

下面是整个数据对象。 成功的：

{"tax":{"order_total_amount":1099.0,"shipping":0.0,"taxable_amount":0.0,"amount_to_collect":0.0,"rate":0.0,"has_nexus":true,"freight_taxable":false,"tax_source":"destination","jurisdictions":{"country":"US","state":"CO","county":"ADAMS","city":"THORNTON"},"breakdown":{"taxable_amount":0.0,"tax_collectable":0.0,"combined_tax_rate":0.0,"state_taxable_amount":0.0,"state_tax_rate":0.0,"state_tax_collectable":0.0,"county_taxable_amount":0.0,"county_tax_rate":0.0,"county_tax_collectable":0.0,"city_taxable_amount":0.0,"city_tax_rate":0.0,"city_tax_collectable":0.0,"special_district_taxable_amount":0.0,"special_tax_rate":0.0,"special_district_tax_collectable":0.0,"line_items":[{"id":"1","taxable_amount":0.0,"tax_collectable":0.0,"combined_tax_rate":0.0,"state_taxable_amount":0.0,"state_sales_tax_rate":0.0,"state_amount":0.0,"county_taxable_amount":0.0,"county_tax_rate":0.0,"county_amount":0.0,"city_taxable_amount":0.0,"city_tax_rate":0.0,"city_amount":0.0,"special_district_taxable_amount":0.0,"special_tax_rate":0.0,"special_district_amount":0.0}]}}}

错误：

{"error":"Bad Request","detail":"to_zip 55478 is not used within to_state AL","status":400}

你可以用。例如：

success: function(data) {
    if(data.hasOwnProperty("tax")) {
        //do stuff
    } else {
        //failed
    }
}

---

这不是函数（）中明显的错误，是吗？很抱歉，修复了，太好了，谢谢。接下来，你会用什么来简单地检查这个对象中是否有错误（不管错误值是多少）{“error”：“Bad Request”，“detail”：“to_zip 55478在to_state AL”，“status”：400}中没有使用。我想你也可以这样做，检查

data.hasOwnProperty（“error”）

。所有这一切都是假设您在同一个响应中有一个或另一个（从来没有两个）。我尝试过，它只在第一种情况下起作用，对数据不起作用。hasOwnProperty（“错误”）-没有显示警报您确定这是您之前评论中的整个

数据

对象吗？它肯定会起作用。看看这把小提琴：