To check the JavaScript object has a value

Question

Can you tell me how to check the JavaScript object has a value ? This vm.occupantDetail.contactDetail object is neither null nor undefined.It looks like as shown below at run time.

It defines as shown below.

 vm.occupantDetail = {
            contactDetail: {},
     };

Answer 1

You can find the it using

Object.keys(vm.occupantDetail.contactDetail).length

Answer 2

It appears from your code that your vm.occupantDetail.contactDetail object is simply an empty object, and the __proto__ property that you are seeing is the protoype property of the Object. If you want to check if an object is null, the following conditional will do the job.

if (obj == null) { ... }

However, it appears that you want to check if an object is empty, which is different. If you want to check if a specified object has no assigned properties, try the following function.

function isEmpty(map) {
   for(var key in map) {
      if (map.hasOwnProperty(key)) {
         return false;
      }
   }
   return true;
}

Answer 3

check it by jQuery.isEmptyObject()

jQuery.isEmptyObject({}); // true
jQuery.isEmptyObject({ foo: "bar" });

https://api.jquery.com/jQuery.isEmptyObject/

Answer 4

Check the length of your object also the length of your keys.

        if (Object.keys(vm.occupantDetail.contactDetail).length > 0)
        { 
            // vm.occupantDetail.contactDetail has values
        }