My question:
Hi! if i have a json like this: {“a”:1,“b”:2}. i want to prove that any other property does not exist. like, “c” not exist but at the same time, “name” do not exist.
I don’t want to do pm.expect(jsonData).not.to.include([“c”,“d”,“name”,“number”,etc])
Hey @spacecraft-astronau2 
, Welcome to the community 
I think what you are looking for, is to validate the property. You can use ‘.hasOwnProperty’ method to check for it:
//example
pm.test("Properties validated",()=>{
pm.expect(response.hasOwnProperty('a')).to.be.true;
pm.expect(response.hasOwnProperty('b')).to.be.true;
pm.expect(response.hasOwnProperty('c')).to.be.false;
// .....etc
})
If your response includes an array of data, have a look at this scenario:
Good luck 
Hope it helps.