If it is not an integer

[m_shafiei2006]

HI

How do I write that an variable is (or not) an integer, or my integer variable does not have value ?

[Keith Watford]

You declare a variable to what you need it to be

int a;

double b;

string c;

[m_shafiei2006]

OK, i know

I declare

int N;

and after that as the situation changes I give a value to N, like N = 2 or N = 1 etc,

N can be 0>, 0< or 0.

but before these situations N does not have a value, I need to do something when N still does not have value.

[Drazen Penic]

Try with NULL: Void Type and NULL Constant 

[m_shafiei2006]

thank you again.

[William Roeder]

It always has a value. If you don't give it one, it is random. Either give it one, or add a boolean variable that states set or not.	m_shafiei2006: N can be 0>, 0< or 0. but before these situations N does not have a value, I need to do something when N still does not have value.
NULL is only for strings and pointers.	drazen64: Try with NULL: Void Type and NULL Constant

[m_shafiei2006]

WHRoeder:

It always has a value. If you don't give it one, it is random. Either give it one, or add a boolean variable that states set or not.	m_shafiei2006: N can be 0>, 0< or 0. but before these situations N does not have a value, I need to do something when N still does not have value.
NULL is only for strings and pointers.	drazen64: Try with NULL: Void Type and NULL Constant

OK, thanks, so I need to use another trick.