iOS 一个很简单的使用类的代码，和.net很像，很好理解

//
//  main.m
//  0824-func
//
//  Created by panba on 15-8-23.
//  Copyright (c) 2015年 panba. All rights reserved.
//

#import <Foundation/Foundation.h>
@interface func:NSObject
-(void) print;
-(void) setfenzi:(int) n;
-(void) setfenmn:(int) m;
-(int) N;
-(int) M;
-(double) num;
@end

@implementation func
{
int fenzin;
int fenmnm;
}
-(void)print
{
NSLog(@"fenzi:%i,fenmn:%i",fenzin,fenmnm);
}
-(void) setfenzi:(int)n
{
fenzin = n;
}
-(void) setfenmn:(int)m
{
fenmnm = m;
}
-(int) N
{
return fenzin;
}
-(int) M
{
return  fenmnm;
}
-(double) num
{
if (fenmnm == 0)
{return NAN;}
else
{
return  fenzin/fenmnm;
}
}

@end

int main(int argc, const char * argv[]) {
@autoreleasepool {
func *afunc = [[func alloc] init];
//func *bfunc = [[func alloc] init];
[afunc setfenzi:1];
[afunc setfenmn:1];
[afunc print];
NSLog(@"=");
NSLog(@"%g",[afunc num]);
//[bfunc setfenzi:1];
//[bfunc setfenmn:0];
//NSLog(@"=");
//NSLog(@"%g",[bfunc num]);
}
return 0;
}