Preprocessor directives tutorial

pages

English

Documents

Écrit par
Kyriakos Stavrou

Publié par
Ofte

Lire

Le téléchargement nécessite un accès à la bibliothèque YouScribe Tout savoir sur nos offres

pages

English

Ebook

Lire

Le téléchargement nécessite un accès à la bibliothèque YouScribe Tout savoir sur nos offres

Publié par

Ofte

Nombre de lectures

Langue

English

Preprocessor Directives This example is called lessons.c. Its purpose is to print in the screen one of two lessons. The output will be either Programming Principles II ######### ####### # # ######## ####### # # # # # # # # # # # # # # # # # # # # ######### # ######## # ######## ####### Or Computer Architecture ######### ####### # ######## ####### # # # # # # # # # # # # # # # # # # # # # ######### # ######## ######## ####### # The whole program is listed below. //----------------------------------------------------------- //This program is for the EPL132 - Laboratory lesson 3 and //aims at showing the usage of IFDEF preprocessor statements // //Author: Kyriakos Stavrou (TSIK) //email : tsik@cs.ucy.ac.cy //Uncomment this line for EPL132 and comment the next one #define EPL321 //#define EPL132 int main() { #ifdef EPL132 printf(" \n \n"); printf(" Programming Principles II \n\n"); printf(" ######### ####### # # ...

Voir

Publié par

Ofte

Nombre de lectures

Langue

English

Preprocessor Directives

This example is called lessons.c. Its purpose is to print in the screen one of two lessons. The output will

be either

Programming Principles II

#########

#######

########

#######

#########

#######

########

#######

#########

########

#######

Computer Architecture

#########

#######

########

#######

#########

#######

########

#######

#########

########

#######

The whole program is listed below.

//-----------------------------------------------------------

//This program is for the EPL132 - Laboratory lesson 3 and

//aims at showing the usage of IFDEF preprocessor statements

//Author: Kyriakos Stavrou (TSIK)

//email : tsik@cs.ucy.ac.cy

//-----------------------------------------------------------

//Uncomment this line for EPL132 and comment the next one

#define EPL321

//#define EPL132

int main()

{

#ifdef EPL132

printf(" \n

\n");

printf(" Programming Principles II

\n\n");

printf(" #########

#######

########

####### \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

####### \n");

printf(" #

\n");

printf(" #

\n");

printf(" #

\n");

printf(" #########

########

####### \n");

#endif

#ifdef EPL321

printf(" Computer Architecture

\n\n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

########

#######

# \n");

#endif

}

In this example you can see two "defines":

#define EPL321

#define EPL132

Case 1

#define EPL321

//#define EPL132

When the program has the line #define EPL321 uncommented and the line #define EPL132 commented,

shaded code will be excluded from the final code to be compiled

//-----------------------------------------------------------

//This program is for the EPL132 - Laboratory lesson 3 and

//aims at showing the usage of IFDEF preprocessor statements

//Author: Kyriakos Stavrou (TSIK)

//email : tsik@cs.ucy.ac.cy

//-----------------------------------------------------------

//Uncomment this line for EPL132 and comment the next one

#define EPL321

//#define EPL132

int main()

{

#ifdef EPL132

printf(" \n

\n");

printf(" Programming Principles II

\n\n");

printf(" #########

#######

########

####### \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

####### \n");

printf(" #

\n");

printf(" #

\n");

printf(" #

\n");

printf(" #########

########

####### \n");

#endif

#ifdef EPL321

printf(" Computer Architecture

\n\n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

########

#######

# \n");

#endif

}

The output of the program will be:

Computer Architecture

#########

#######

########

#######

#########

#######

########

#######

#########

########

#######

Case 2

//#define EPL321

#define EPL132

In the case that the line #define EPL321 comented and the line #define EPL132 uncommented, the code

that will be excluded is the one shown as shaded in the following listing.

//-----------------------------------------------------------

//This program is for the EPL132 - Laboratory lesson 3 and

//aims at showing the usage of IFDEF preprocessor statements

//Author: Kyriakos Stavrou (TSIK)

//email : tsik@cs.ucy.ac.cy

//-----------------------------------------------------------

//Uncomment this line for EPL132 and comment the next one

//#define EPL321

#define EPL132

int main()

{

#ifdef EPL132

printf(" \n

\n");

printf(" Programming Principles II

\n\n");

printf(" #########

#######

########

####### \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

####### \n");

printf(" #

\n");

printf(" #

\n");

printf(" #

\n");

printf(" #########

########

####### \n");

#endif

#ifdef EPL321

printf(" Computer Architecture

\n\n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

########

#######

# \n");

#endif

}

The output of the program will be:

Programming Principles II

#########

#######

########

#######

#########

#######

########

#######

#########

########

#######

Case 3

//#define EPL132

In the case that the line #define EPL321 comented and the line #define EPL132 uncommented, the code

that will be excluded is the one shown as shaded in the following listing.

//-----------------------------------------------------------

//This program is for the EPL132 - Laboratory lesson 3 and

//aims at showing the usage of IFDEF preprocessor statements

//Author: Kyriakos Stavrou (TSIK)

//email : tsik@cs.ucy.ac.cy

//-----------------------------------------------------------

//Uncomment this line for EPL132 and comment the next one

//#define EPL321

//#define EPL132

int main()

{

#ifdef EPL132

printf(" \n

\n");

printf(" Programming Principles II

\n\n");

printf(" #########

#######

########

####### \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

####### \n");

printf(" #

\n");

printf(" #

\n");

printf(" #

\n");

printf(" #########

########

####### \n");

#endif

#ifdef EPL321

printf(" Computer Architecture

\n\n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

########

#######

# \n");

#endif

}

The output of the program will be:

This is because all print commands are excluded from the final code to be compiled.

Case 4

#define EPL321

#define EPL132

In the case that the line #define EPL321 comented and the line #define EPL132 uncommented, the code

that will be excluded is the one shown as shaded in the following listing.

//-----------------------------------------------------------

//This program is for the EPL132 - Laboratory lesson 3 and

//aims at showing the usage of IFDEF preprocessor statements

//Author: Kyriakos Stavrou (TSIK)

//email : tsik@cs.ucy.ac.cy

//-----------------------------------------------------------

//Uncomment this line for EPL132 and comment the next one

#define EPL321

#define EPL132

int main()

{

#ifdef EPL132

printf(" \n

\n");

printf(" Programming Principles II

\n\n");

printf(" #########

#######

########

####### \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

####### \n");

printf(" #

\n");

printf(" #

\n");

printf(" #

\n");

printf(" #########

########

####### \n");

#endif

#ifdef EPL321

printf(" Computer Architecture

\n\n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

#######

########

#######

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #

# \n");

printf(" #########

########

#######

# \n");

#endif

}

The output of the program will be:

Programming Principles II

#########

#######

########

#######

#########

#######

########

#######

#########

########

#######

Computer Architecture

#########

#######

########

#######

#########

#######

########

#######

#########

########

#######

Voir

Univers
Ebooks
Livres audio
Presse
Podcasts
BD
Documents

Livre audio en ligne - Développement personnel Livre en ligne Tout le catalogue Tous les Intérêts

Preprocessor directives tutorial

YouScribe

Le catalogue

Le service

Les conditions