基于Object-C语言完成基本算术运算

 //

    
 //  main.m
    
 //  prog1
    
 //
    
 //  Created by songjs on 15-1-6.
    
 //  Copyright (c) 2015年 songjs. All rights reserved.
    
 //
    
  
    
 #import <Foundation/Foundation.h>
    
 //实现一个简单的4则运算计数器
    
  
    
 @interface Calculator:NSObject
    
 //累加方法
    
 -(void) setAccumulator:(double) value;
    
 -(void) clear;
    
 -(double) accumulator;
    
  
    
 //算术方法
    
 -(void) add:(double) value;
    
 -(void) subtract: (double) value;
    
 -(void) multiply:(double) value;
    
 -(void) divide:(double) value;
    
 @end
    
  
    
 @implementation Calcul