Objective-C Xcode 8.2.1编译错误 - 类 - NSLog

Question

我试图在Xcode 8.2.1中编译此代码。这是一个非常简单的课程，但它没有编译。

代码：

#import <Foundation/Foundation.h>

@interface Fraction: NSObject

- (void) print;
- (void) setNumerator: (int) n;
- (void) setDenominator: (int) d;

@end

@implementation Fraction
{
    int numerator;
    int denominator;
}

- (void) print
{
    NSLog (@"%i/%i", numerator, denominator); // <--- possible problem here?

}

- (void) setNumerator: (int) n
{
    numerator = n;
}

- (void) setDenominator: (int) d
{
    denominator = d;
}

@end

int main (int argc, char * argv[])
{
    @autoreleasepool {
        Fraction *myFraction;

        myFraction = [Fraction alloc];
        myFraction = [myFraction init];

        [myFraction setNumerator: 1];
        [myFraction setDenominator: 3];

        NSLog (@"The value of myFraction is:");
        [myFraction print]; // <---- possible problem here
    }
    return 0;
}

输出： 2017-02-08 17：13：00.789 prog3point2 [8643：13648415] myFraction的值是： （LLDB）

libdyld.dylib`start:
    0x7fff9f7125ac <+0>: nop    
    0x7fff9f7125ad <+1>: movl   %eax, %edi
    0x7fff9f7125af <+3>: callq  0x7fff9f7125e0            ; symbol stub for: exit
    0x7fff9f7125b4 <+8>: hlt    

非常感谢，感谢此处的任何指导。