Question

#import <Foundation/Foundation.h>

@interface Factorial : NSObject 
+(int) factorial:(int) n;
@end

@implementation Factorial

+(int) factorial:(int)n
{
    if (n==0) {
        return 1;
    }
    else
    {
        return [self factorial:n]*[self factorial:n-1];
    }
}

@end

int main (int argc, const char * argv[])
{
    int i = [Factorial factorial:5];
    NSLog(@"%d", i);
    return 0;
}

what is the problem with this code?? i am new in objective-c (i am from c background)
Or, i am getting wrong concept about objective c??

(Compiler generating ..)
GNU gdb 6.3.50-20050815 (Apple version gdb-1708) (Mon Aug  8 20:32:45 UTC 2011)
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This GDB was configured as "x86_64-apple-darwin".tty /dev/ttys002
sharedlibrary apply-load-rules all
[Switching to process 1413 thread 0x0]
warning: Unable to restore previously selected frame.
(gdb) 

and getting stuck at line +(int) factorial:(int) n at the @implementation resulting EXC_BAD_ACESS.

Thanks

Answer 1

I am not familiar with ObjC, but lines:

+(int) factorial:(int)n
    //...
    return [self factorial:n]*[self factorial:n-1];
    //                      ^

look suspicious for me. It means that for n != 0 you will get endless recursion and face stack overflow 🙂