Ex 6.4

[byrsky]

Code: (Objective-C)

#import <Foundation/Foundation.h>

@interface Calculator : NSObject {
@private
    double accumulator;
    double memory;
}

-(void) setAccumulator: (double) value;
-(void) clear;
-(double) accumulator;

-(double) add: (double) value;
-(double) subtract: (double) value;
-(double) multiply: (double) value;
-(double) divide: (double) value;

-(double) changeSign; 
-(double) reciprocal; 
-(double) xSquared;   

-(void) memoryClear;                    
-(double) memoryStore;                      
-(double) memoryRecall;                    
-(double) memoryAdd: (double) value;        
-(double) memorySubtract: (double) value;  

@end

@implementation Calculator

-(void) setAccumulator:(double)value
{
    accumulator = value;
}

-(void) clear
{
    accumulator = 0;
}

-(double) accumulator 
{
    return accumulator;
}

-(double) changeSign
{
    return (unsigned) accumulator;
}

-(double)reciprocal 
{
    accumulator = 1 / accumulator;
    return accumulator;
}

-(double) xSquared
{
    accumulator *= accumulator;
    return accumulator;
}

-(void)memoryClear
{
    memory = 0;
}

-(double)memoryStore
{
    memory = accumulator;
    return memory;
}

-(double)memoryRecall
{
    accumulator = memory;
    return accumulator;
}

-(double)memoryAdd:(double)value
{
    memory += value;
    return memory;
}

-(double)memorySubtract:(double)value {
    memory -= value;
    return memory;
}


-(double) add:(double)value
{
    accumulator += value;
    return accumulator;
}

-(double) subtract:(double)value
{
    accumulator -= value;
    return accumulator;
}

-(double) multiply:(double)value
{
    accumulator *= value;
    return accumulator;
}

-(double) divide:(double)value
{
    if (value != 0) {
        accumulator /= value;   
    } else {
        NSLog(@"Error: / 0");
        
    }
    
    return accumulator;
}

@end


int main (int argc, const char * argv[])
{
    
    @autoreleasepool {
        
        Calculator *deskCalc = [[Calculator alloc]init];
        
        double value1;
        char operator;
        
        NSLog(@"Input number & operator:");
        
        do {
            
            scanf("%lf %c", &value1, &operator);
            
            switch (operator) {
                case 'S':
                    [deskCalc setAccumulator:value1];
                    NSLog(@"= %f", [deskCalc accumulator]);
                    break;
                case '+':
                    
                    [deskCalc add:value1];
                    NSLog(@"= %f", [deskCalc accumulator]);
                    break;
                case '-':
                    
                    [deskCalc subtract:value1];
                    NSLog(@"= %f", [deskCalc accumulator]);
                    break;
                case '*':
                    
                    [deskCalc multiply:value1];
                    NSLog(@"= %f", [deskCalc accumulator]);
                    break;
                case '/':
                    
                    [deskCalc divide:value1];
                    NSLog(@"= %f", [deskCalc accumulator]);
                    break;
                case 'E': 
                    NSLog(@"End");
                    break;
                default:
                    NSLog(@"Oparator Error");
                    break;
            }
            
            
        } while (operator != 'E');    
        
        
        
        
        
        
    }
    return 0;
}