Objective-C. Simplest Data Types

I just made a simple application: New Project from the File menu -> Command Line Utility -> Foundation Tool. Then put the following code:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) 
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    int            intVar = 100;
    long int    longIntVar = 131071100L;
    float        floatVar = 331.79;
    double        doubleVar = 8.44e+11;
    long double    longDoubleVar = 1.234e+7L;
    char        charVar = 'W';
    
    NSLog(@"intVar = %i", intVar);
    NSLog(@"longIntVar = %li", longIntVar);
    NSLog(@"floafVar = %f", floatVar);
    NSLog(@"doubleVar = %e", doubleVar);
    NSLog(@"longDoubleVar = %Le", longDoubleVar);
    NSLog(@"doubleVar = %g", doubleVar);
    NSLog(@"charVar = %c", charVar);
    
    [pool drain];
    return 0;
}

Then launch the console and press Build & Go:

There is one special type in Objective-C. This is id. This type is used to store objects of any type. I think it is something like void*. So it is possible to write the following code:

id everything = (id)intVar;
NSLog(@"variable of id type = %i", everything);