使用JQuery检查JSON数组中是否存在键

I have done AJAX validation and validated message is returned as a JSON array. Therefore I need to check whether the keys, like name and email, are in that JSON array.

我已经完成了AJAX验证，验证消息作为JSON数组返回。因此，我需要检查键，比如名称和电子邮件，是否在JSON数组中。

{"name":{"isEmpty":"Value is required and can't be empty"},
 "email":{"isEmpty":"Value is required and can't be empty"}}

Only if the key name is present, I need to write an error message to the name field. Following is the code to display an error if fields is entered

只有当键名出现时，我才需要向name字段写入错误消息。以下是在输入字段时显示错误的代码。

if(obj['name']'isEmpty']!=""){                                 
 $('#name').after(c1+"<label class='error'>"+ obj['name']['isEmpty']+"</label>");
}                                       
if(obj['email']['isEmpty']!="" ){ 
         $('#email').after(c4+"<label class='error'>"+ obj['email']['isEmpty']+"</label>");
}

But if the name field is entered, it will not be in JSON array. So the checking statement if(obj['name']['isEmpty']!="") will result in an error obj.name not found.

但是如果输入了name字段，它就不会是JSON数组。因此，检查语句if(obj['name']['isEmpty']!

It is not necessary to have key name in the array. At same time I need to check for this to display the error if the array possesses the key name.

在数组中不需要有键名。同时，我需要检查它，以显示如果数组拥有密钥名的错误。

4 个解决方案

#1

use javascript's hasOwnProperty function,

使用javascript的hasOwnProperty函数,

if(json_object.hasOwnProperty('name')){
//do struff
}

#2

No need of JQuery simply you can do

不需要JQuery就可以了

if(yourObject['email']){
 // what if this property exists.
}

as with any value for email will return you true, if there is no such property or that property value is null or undefined will result to false

如果没有这样的属性，或者属性值为null或未定义，则将导致false

#3

if(typeof theObject['key'] != 'undefined'){
     //key exists, do stuff
}

//or

if(typeof theObject.key != 'undefined'){
    //object exists, do stuff
}

I'm writing here because no one seems to give the right answer..

我写这篇文章是因为似乎没有人给出正确的答案。

I know it's old...

我知道这是老…

Somebody might question the same thing..

有人可能会问同样的问题。

#4

if you have an array

如果你有一个数组。

var subcategories=[{name:"test",desc:"test"}];

function hasCategory(nameStr) {
        for(let i=0;i<subcategories.length;i++){
            if(subcategories[i].name===nameStr){
                return true;
            }
        }
        return false;
    }

if you have an object

如果你有一个物体。

var category={name:"asd",test:""};

if(category.hasOwnProperty('name')){//or category.name!==undefined
   return true;
}else{
   return false;
}

#1