“Output”: [
        {

            "id_": “123”
            "first_name": “Testing”,
            "last_name": “Validation”,
            "state": “VA”,
            “yearofbirth”: 1983,
             "currentcompany”: null
        },
        {
            "id": “456”
            "first_name": “Testing”,
            "last_name": “Validation”,
            "state": “VA”,
            “yearofbirth”: 1975,
             "currentcompany”: null        
	},
        {
            id": “456”
            "first_name": “Testing”,
            "last_name": “Validation”,
            "state": “VA”,
            “yearofbirth”: 1990,
            "current_employment": {
			 “company number”: 3455,
               		   "name": “XYZ Company”,
        }

consider above is the response. I want to validate "id, firstname, last name, state, yearofbirth, current employment is present in response using array list using loop.

The problem is i am able to get the value of every key and validate. but unable to take only "Key" and check if its present.