21-5 with ARC pt 3 Calculator code

[Fred]

part 3 Calculator code

Code: (Objective-C)

//  Calculator.h
//  Fraction-Calculator
//
//  Created by Fred H Koch on 10/25/11.
//

#import <UIKit/UIKit.h>
#import "Fraction.h"

@interface Calculator : NSObject
{
    Fraction *operand1;
    Fraction *operand2;
    Fraction *accumulator;
}

@property (strong, nonatomic) Fraction *operand1, *operand2, *accumulator;

- (Fraction *) performOperation: (char) op;
- (void) clear;

@end

Code: (Objective-C)

//  Calculator.m
//  Fraction-Calculator
//
//  Created by Fred H Koch on 10/25/11.
//

#import "Calculator.h"

@implementation Calculator

@synthesize operand1, operand2, accumulator;

- (id) init
{
    self = [super init];
    
    if (self) {
        operand1 = [[Fraction alloc] init];
        operand2 = [[Fraction alloc] init];
        accumulator = [[Fraction alloc] init];
    }
    
    return self;
}

-(void) clear
{
    accumulator.numerator = 0;
    accumulator.denominator = 1;
}

- (Fraction *) performOperation:(char)op
{
    Fraction *result;
    
    switch (op) {
        case '+':
            result = [operand1 add: operand2];
            break;
        case '-':
            result = [operand1 subtract: operand2];
            break;
        case '*':
            result = [operand1 multiply: operand2];
            break;
        case '/':
            result = [operand1 divide: operand2];
            break;
    }
    
    accumulator.numerator = result.numerator;
    accumulator.denominator = result.denominator;
    
    return accumulator;
}

@end