Chapter 4 Exercise 2

[adrianK]

Hello!
It first try for once!!

// Temperature  F, C

#import <Foundation/Foundation.h>

// Class section

@interface Degree: NSObject
{   
   float celsius;
}

// accumulator methode

-(void) setCelsius: (float) value;
-(void) clear;
-(float) celsius;


// arithmetic methode

-(void) fahrenheit: (float) value;
-(void) fahzero: (float) value;
-(void) result: (float) value;


@end

// Methods section

@implementation Degree

-(void) setCelsius: (float) value
{
   celsius = value;
}

-(void) clear
{
   celsius = 0;
}

-(float) celsius
{
   return celsius;
}

-(void) fahrenheit: (float) value
{
   celsius += value;
}

-(void) fahzero: (float) value
{
   celsius -= value;
}

-(void) result: (float) value
{
   celsius /= value;
}


@end
   
// Programming section
   
int main(int argc, const char *agrv[])
   {
      NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
      Degree *Temp;
      
      Temp = [[Degree alloc] init];
      
      [Temp clear];
      [Temp setCelsius: 0];
      [Temp fahrenheit: 27];
      [Temp fahzero: 32];
      [Temp result: 1.8];
      
      
      NSLog (@" (27:where? I don't know...) Fahenheit to Celsius: %g",
            [Temp celsius]);
      
      [Temp release];
      [pool drain];
      
      return 0;
}

NSLog (@" (27:where? I don't know...) Fahrenheit to Celsius: %g", [Temp celsius]);



[Session started at 2010-04-17 00:09:25 +0900.]
2010-04-17 00:09:25.470 Prog6[1484:10b]  (27:where? I don't know...) Fahrenheit to Celsius: -2.77778

The Debugger has exited with status 0.

[skochan]

I think you've made the solution to this exercise overly-complex by modeling it after the Calculator class.   Other readers have also tackled this problem by defining a new class.

This problem can be more easily solved without defining a new class and by just evaluating the formula given in the exercise.   I think I'll state that in the next edition of the book!

Cheers,

Steve Kochan

[adrianK]

Hello Steve.

Thanks for confirming.

[jdelamater]

adrian, if it helps you out at all, here's my solution...not saying it is the best way, just what i came up with.

Code: (Objective-C)

#import <Foundation/Foundation.h>

@interface TempConvert : NSObject {
	int		farenheit;
	float	celcius;
}

-(void) setF: (int) value;
-(int) farenheit;
-(float) celcius;

@end

@implementation TempConvert

-(void) setF: (int) value {
	farenheit = value;
}

-(int) farenheit {
	return farenheit;
}

-(float) celcius {
		return celcius = (float) (farenheit - 32) / 1.8;
}

@end


int main (int argc, const char * argv[]) {
	NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	
	TempConvert *tempChange;
	tempChange = [[TempConvert alloc] init];
	
	[tempChange setF: 54];
	
	NSLog (@" %iF is %fC", [tempChange farenheit], [tempChange celcius]);
	
	[pool drain];
	return 0;
}

[adrianK]

Thank you! jdelamater.

Wow, a lot of sources has been reduced. I'll see.

[iLikeMyiPhone]

I think Stephen was referring to this. I am glad my C basics are still in place, compiled int he first run!

Code: (Objective-C)

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

    // insert code here...
	//c = (f-32)/1.8
	double c = 0, f = 62;
	c = (f-32)/1.8;
	NSLog(@"The value in Celsius is %g", c);
    [pool drain];
    return 0;
}

[MBB]

Code: (Objective-C)

	
#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
		
	/* Write a program that converts 27˚ from degress Fahrenheit (F) to degrees Celcius (C)
	 using the following formula: c = (F-32) / 1.8 */
	
	double f = 27, c;
	c = (f - 32) / 1.8;
	
	NSLog(@"27˚F converted to ˚C is %g", c);	
	
    [pool drain];
    return 0;
}