I am creating an alternative function of IntegerQ[] function. Now I don't want any output. I just want my function to check whether this is integer or not. I'm gonna use it in another code. My code looks like;

IntQ[n_] := Block[{}, GP = 0;
  {j = 0;
   If[n >= 0,
        For[i = n, i > 0, i--, j++],
        For[i = (-n), i > 0, i--, j++]]};
  {If[j == n, True, False]};
  ]

It is not working. I just want to know where is the problem, why the problem is causing and how to solve it? Generally IntegerQ[6] would return True as an output and in other function it wouldn't return anything but we can use that value actually. So that's where my problem is.