[javascript] Check if key exists in JSON object using jQuery

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.

{
    "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

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 the following error:

obj.name not found

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.

Use JavaScript's hasOwnProperty() function:

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

No need of JQuery simply you can do

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

if you have an array

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

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

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

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..

I know it's old...

Somebody might question the same thing..