iOS修炼之道：如何理解c类语言中的"."和"->"的作用

//
//  main.m
//  AddressBook
//
//  Created by admin on 15/11/26.
//  Copyright © 2015年 admin. All rights reserved.
//

///////////////////fraction.h///////////////////

#import <Foundation/Foundation.h>

//-------- @interface Part  --------

@interface Fraction: NSObject
{
@public
    int numerator;
}

-(void) setNumerator: (int) n;
-(int) numerator;

@end


//--------- @implementation Part -----

@implementation Fraction

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

-(int) numerator
{
    return numerator;
}
@end


//--------------    Program Part   ---------------
int main()
{
    @autoreleasepool {
        Fraction *myFraction = [[Fraction alloc] init];
        [myFraction setNumerator: 1];
        myFraction.numerator = 3;
        NSLog(@"numerator get is %i", myFraction.numerator);
        NSLog(@"numerator get is %i", myFraction->numerator);
        NSLog(@"numerator get is %i", [myFraction numerator]);
        
    }
    return 0;
}