Exercise #7

[jonthornham]

Here is my answer to Exercise #7

Code: (Objective-C)

// Rectangle Program 

#import <Foundation/Foundation.h>

// @interface Section
@interface Rectangle: NSObject
{
	int width;
	int height;
	int area;
	int perimeter;
}

-(void) setWidth: (int) w;
-(void) setHeight: (int) h;
-(int) width;
-(int) height;
-(int) area;
-(int) perimeter;
@end

// @implementation Section
@implementation Rectangle
-(void) setWidth: (int) w
{
	width = w;
}

-(void) setHeight: (int) h
{
	height = h;
}

-(int) width
{
	return width;
}

-(int) height
{
	return height;
}

-(int) area
{
	area = width * height;
	return area;
}

-(int) perimeter
{
	perimeter = (2 * width) + (2 * height);
	return perimeter;
}
@end

// main
int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	
	Rectangle *rectangle1 = [[Rectangle alloc] init];
	
	[rectangle1 setWidth: 18];
	[rectangle1 setHeight: 36];
	
	NSLog(@"The width of the rectangle is %i", [rectangle1 width]);
	NSLog(@"The height of the rectangle is %i", [rectangle1 height]);
	NSLog(@"The area of the rectangle is %i", [rectangle1 area]);
    NSLog(@"The perimeter of the rectangle is %i", [rectangle1 perimeter]);
	
	[rectangle1 release];
    [pool drain];
    return 0;
}

Take care,

Jon

[skochan]

Since the area and perimeter are calculated each time the respected method is called, there's no purpose to store them as instance variables in your objects.   

Cheers,

Steve Kochan