Completed exercises from 'Programming in Objective-C' - because why not?

ch3q7-main.m

//
//  main.m
//  ch3q7
//
//  Created by Ellis Grouse on 15/05/2012.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//  Book exercise: Chapter 3 Q7
//  Make a class called XYPoint that holds 2 coordinates x,y and can set/get them separately
//  Write functionality to output the information
//

#import <Foundation/Foundation.h>

// ----- @interface section -----
@interface XYPoint: NSObject

// Instance methods
-(void) print;
-(void) setX: (int) inputX;
-(void) setY: (int) inputY;
-(int) x;
-(int) y;

@end

// ----- @implementation section -----
@implementation XYPoint
{
  int x, y;
}

// -- SETTERS
-(void) setX:(int)inputX
{
  // Set x value to input
  x = inputX;
}

-(void) setY:(int)inputY
{
  // Set y value to input
  y = inputY;
}

// -- GETTERS
-(int) x
{
  return x;
}

-(int) y
{
  return y;
}

// -- OUTPUT
-(void) print
{
  NSLog(@"The coordinates are: %i,%i", x, y);
}

@end

// ----- program run section
int main (int argc, const char * argv[])
{

  @autoreleasepool {
      
    // Allocate and initialise object
    XYPoint *coord = [[XYPoint alloc] init];
    
    // Set coordinate values
    [coord setX: 3];
    [coord setY: 9];
    
    // Output
    [coord print];
    
    // And again, with getters
    NSLog(@"It is: %i,%i", [coord x], [coord y]);
      
  }
    return 0;
}

ch4q2-main.m

//
//  main.m
//  ch4q2
//
//  Created by Ellis Grouse on 15/05/2012.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//  Book exercise: Chapter 4 Q2
//  Write a program that converts 27°F to °C using the following formula:
//    C = ( F - 32 ) / 1.8
//

#import <Foundation/Foundation.h>

// ==== PROGRAM
int main (int argc, const char * argv[])
{

  @autoreleasepool
  {
    // Run the program
    float result;
    int fahrenheit = 27;
    
    result = ( fahrenheit - 32 ) / 1.8;
    
    NSLog(@"Result: %g", result);
  }
  return 0;
}

ch4q7-main.m

//
//  main.m
//  ch4q7
//
//  Created by Ellis Grouse on 15/05/2012.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//  Book exercise: Chapter 4 Q 7
//  Create an object to hold info on a rectangle
//  With height, width, and functions to calculate area and perimeter
//

#import <Foundation/Foundation.h>

// ==== INTERFACE
@interface Rectangle : NSObject {
  @private
}

// Setters
-(void) setWidth: (int) w;
-(void) setHeight: (int) h;

// Getters
-(int) width;
-(int) height;
-(int) area;
-(int) perimeter;

@end


// ==== IMPLEMENTATION
@implementation Rectangle
{
  int width, height;
}

// Setters
-(void) setWidth:(int)w
{
  width = w;
}

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

// Getters
-(int) width
{
  return width;
}

-(int) height
{
  return height;
}

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

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

@end

// ==== PROGRAM CODE
int main (int argc, const char * argv[])
{
  @autoreleasepool
  {
    // Create a new Rectangle object
    Rectangle *rect = [[Rectangle alloc] init];
    
    // Assign values to our rectangle
    [ rect setWidth: 5 ];
    [ rect setHeight: 9 ];
    
    // Create some output
    NSLog(@"The rectangle has the following parameters.\n Width: %i  Height: %i\n Area: %i  Perimeter: %i",
          [ rect width ], [ rect height ], [ rect area ], [ rect perimeter] );
  }
}

ch5q1-main.m

//
//  main.m
//  ch5q1
//
//  Created by Ellis Grouse on 15/05/2012.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//  Book exercise: Chapter 5 Q 1
//  Write a program to generate and display a table of n and n2, for integer values of n ranging from 1 through 10. Be sure to print the appropriate column headings.
//

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{
  @autoreleasepool
  {
    // Variables
    int n;
    
    // Output headings
    NSLog(@" n  n^2 ");
    NSLog(@"--------");
    
    // Counter
    for (n = 1; n <= 10; n++) {
      NSLog(@"%2i  %3i", n, n * n);
    }
  }
  
  // Return 0
  return 0;
}

ch6q1-main.m

//
//  main.m
//  ch6q1
//
//  Created by Ellis Grouse on 15/05/2012.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//  Chapter 6
//  1. Write a program that asks the user to type in two integer values. Test these two numbers to determine whether the first is evenly divisible by the second and then display an appropriate message at the terminal.
//

#import <Foundation/Foundation.h>

// Program coding
int main( int argc, const char * argv[] )
{
  @autoreleasepool
  {
    // Variables
    int first, second;
    bool isEven;
    
    // Take user input
    NSLog( @"Please type in two integer variables, separated by a space." );
    scanf( "%i %i", &first, &second );
    
    // Divide
    int division = first / second;
    
    // Check if division is an even number
    if( division % 2 == 0 )
      isEven = YES;
    
    // Output
    NSLog( @"You entered %i and %i.", first, second );
    NSLog( @"%i / %i is: %i", first, second, division );
    if( isEven )
      NSLog( @"%i is evenly divisible by %i", first, second );
    else
      NSLog( @"%i is not evenly divisible by %i", first, second );
  }
  
  return 0;
}

ch6q4-main.m

//
//  main.m
//  ch6q4
//
//  Created by Ellis Grouse on 15/05/2012.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//  Chapter 6
/*  4. Write a program that acts as a simple printing calculator. The program should allow the user to type in expressions of the following form:
      number  operator
    The program should recognize the following operators:
      +   -   *   /   S   E   */

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{
  @autoreleasepool
  {
    // Variable declarations
    float accumulator, inputValue;
    char inputOperator;
    bool isRunning = YES;
    
    // Begin execution
    NSLog( @"Beginning calculator operation..." );
    do
    {
      // Take user input
      scanf( "%f %c", &inputValue, &inputOperator );
      
      // Switch between the different operators the user may have input
      switch( inputOperator )
      {
        // Set accumulator to input value
        case 'S': case 's':
          accumulator = inputValue;
          break;
          
        // End operation
        case 'E': case 'e':
          isRunning = NO;
          break;
          
        // Addition
        case '+':
          accumulator += inputValue;
          break;
        
        // Subtraction
        case '-':
          accumulator -= inputValue;
          break;
        
        // Multiplication
        case '*':
          accumulator *= inputValue;
          break;
        
        // Division
        case '/':
          accumulator /= inputValue;
          break;
          
        // Default operation - fallback for invalid
        default:
          NSLog( @"Invalid operator. Valid operators: + - * / S E" );
      }
      
      // Output the current value of the accumulator
      NSLog( @"= %f", accumulator );
    }
    while( isRunning == YES );
  }
  
  return 0;
}