How to delete an object through a function in JS?

Question

JavaScript

var person = { 
  'firstName': 'Alex',
  'lastName': 'Medvedev',
  'getFullName': function() {
    return person.firstName + ' ' + this.lastName;
  }
}

console.log(person);

// killer functions
var kill = function(obj) { // delete the object - does not work
  delete obj;
}

var kill2 = function(obj) { // replace with an empty object - does not work
  obj = {};
}

var kill3 = function(obj) { // manually delete each object property - works!
  delete obj.firstName;
  delete obj.lastName;
  delete obj.getFullName;h
}

kill(person);
console.log(person);

kill2(person);
console.log(person);

kill3(person);
console.log(person);

As you can see, only manually you can delete each property of an object, but not reset the entire object at once. I have no goals for this, I just study the language. I learned that you can call a function through another function, but was surprised when I could not nullify the object.
Is there a good practice solution here?
PS: MDN read:
https://developer.mozilla.org/en-US/docs/Web/JavaS...

Answer 1

var kill = function(obj) { // delete the object - does not work
delete obj;
}

call kill(obj); removes an object that is in the context of the function itself, in other words, something like this happens:
there is var a = { ... };
kill(a) /* obj = a; delete obj */ in other words deletes the clone

var kill2 = function(obj) { // replace with an empty object - does not work
obj = {};
}

here the object is cleared and
the question is not deleted, why did the built-in function not please? what should happen? just delete a;
and if through the function:

function kill_obj (obj) {
detele window[obj];
}

kill_obj('str_name');

Answer 2

If you just
don't like it, maybe

var kill4 = function (str) {
  eval('delete ' + str);
}

kill4('person');

Answer 3

Object.keys(obj).forEach(function(key){
  delete obj[key];
});

Answer 4

In JS, objects are not deleted manually, this is handled by the garbage collector.
If you want to remove all enumerable properties from an object, see answer from MNB