Programming in C

414 Chapter 19 Object-Oriented Programming

Program 19.1 Working with Fractions in C

// Simple program to work with fractions

#include <stdio.h>

typedef struct {

int numerator;

int denominator;

} Fraction;

int main (void)

{

Fraction myFract;

myFract.numerator = 1;

myFract.denominator = 3;

printf ("The fraction is %i/%i\n", myFract.numerator, myFract.denominator);

return 0;

}

Program 19.1 Output

The fraction is 1/3

The next three sections illustrate how you might work with fractions in Objective-C,

C++, and C#, respectively.The discussion about OOP that follows the presentation of

Program 19.2 applies to OOP in general, so you should read these sections in order.

Defining an Objective-C Class to Work with

Fractions

The Objective-C language was invented by Brad Cox in the early 1980s.The language

was based on a language called SmallTalk-80 and was licensed by NeXT Software in

1988.When Apple acquired NeXT in 1988, it used NEXTSTEP as the basis for its Mac

OS X operating system. Most of the applications found today on Mac OS X are written

in Objective-C.

Program 19.2 shows how you can define and use a Fractionclass in Objective-C.

Program 19.2 Working with Fractions in Objective-C

// Program to work with fractions – Objective-C version

#import <stdio.h>

#import <objc/Object.h>