In Objective-C, are int variables that haven't been assigned a value nil?

Question

If I have this in my .h file:

int index;

And then in the .m file I have:

if (index == nil)
         


        

Answer 1

nil is a specific value reserved for Objective-C object pointers. It is very similar to NULL (0) but has different semantics when used with message passing.

local primitive data types like int's are not initialized in Objective-C. The value of index will not be defined until you write to it.

void foo () {
   //initialize local variable
   int x = 5;
}

//initialise static variable
static int var = 6;