ios-A+B经典问题

////  main.m//  a+b//#import <Foundation/Foundation.h>#import "Calcultor.h"int main(int argc, const char * argv[]){    Calcultor * cal = [[Calcultor alloc]init];        [cal setA:10];    [cal setB:20];        int result = [cal add];    NSLog(@"%d",result);        NSLog(@"%d",[cal sub:10 andb1:10]);    return 0;}

////  Calcultor.h//  a+b//#import <Foundation/Foundation.h>@interface Calcultor : NSObject{    int _a;    int _b;}/*set get */@property int a;@property int b;-(int)add;-(int)sub:(int)a1 andb1:(int)b1;@end

////  Calcultor.m//  a+b//#import "Calcultor.h"@implementation Calcultor-(id)init{    self = [super init];    if(self != nil)    {        _a = 0;        _b = 0;    }    return self;}-(int)add{    return _a + _b;    //NSLog(@"a+b");}-(int)sub:(int)a1 andb1:(int)b1;{    _a = a1;    _b = b1;    return _a + _b;}@end