คำสั่ง การประมวลผลก่อน

��ҵ�ҧ� ��ٻẺ��ç��ҧ੾�з��ᵡ��ҧ�ѹ� ��Ѻ��ҫ� ��ç��ҧ��ӴѺ��¹�ѧ��

สารบัญ Show

�ٻẺ
��ǹ��żš�͹ (Preprocessor statement)
��ǹ��С�ȵ��ǹ��ҧ (Global declarations statement)
��ǹ�ѧ��ѹ��ѡ (Function main)
��ǹ�ѧ��ѹ��˹��ͧ (User-defined function)
��ǹ͸Ժ�� (Program Comment)
��á�ͧ�ѹ

��ǹ��żš�͹ (Preprocessor statement)
��ǹ��С�ȵ��ǹ��ҧ (Global declarations statement)
��ǹ�ѧ��ѹ��ѡ (Function main)
��ǹ�ѧ��ѹ��˹��ͧ (User-defined function)
��ǹ͸Ժ�� (Program Comment)

�ٻẺ

1	//StructureOfC.c	//��ǹ͸Ժ��
2	/Program by Jaturapad Pratoom/	//��ǹ͸Ժ��
3	#include <stdio.h>	//��ǹ��żš�͹

int a,b;

//��ǹ��С�ȵ��ǹ��ҧ

int sum(int x, int y);

//��ǹ��С�ȵ��ǹ��ҧ

int main()

//��ǹ�ѧ��ѹ��ѡ main()

{

// ��鹿ѧ��ѹ��ѡ main()

int c;

//��ǹ��С�ȵ��÷�ͧ��

printf("Input number 1: ");

//��㹿ѧ��ѹ��ѡ main()

scanf("%d", &a);

//��㹿ѧ��ѹ��ѡ main()

printf("Input number 2: ");

//��㹿ѧ��ѹ��ѡ main()

scanf("%d", &b);

//��㹿ѧ��ѹ��ѡ main()

c = sum( a, b);

//��㹿ѧ��ѹ��ѡ main()

printf("\n%d + %d = %d", a, b,c);

//��㹿ѧ��ѹ��ѡ main()

getch();

//��㹿ѧ��ѹ��ѡ main()

}

// ��ѧ��ѹ��ѡ main()

int sum(int x, int y)

//�ѧ��ѹ sum()

{

// ��鹿ѧ��ѹ sum()

return(x + y);

//��㹿ѧ��ѹ sum()

}

// ��ѧ��ѹ sum()

��ǹ��żš�͹ (Preprocessor statement)

��ǹ��е�ͧ�շء�� Ҩ��¡��ǹ��Ǣͧ�� 繵�ͧ��˹��㹵͹�� ¨Т�鹵鹴��ͧ�� # ��¤��礷տ (Directive) ��ͧ��á�˹��

#include <stdio.h> �� #include "stdio.h"

��¶֧��ü�ǡ�δ�� stdio.h ��ҹ ��駹��δ�� stdio.h ��鹨��쪹Դ��ͤ�� (Text file) ��ա�û�С�Ȥ�ҵ�� Ф�Ҥ��ҧ� ��èؿѧ��ѹ�ҵðҹ��ҧ� ��Ҵ��¡ѹ��Ǵ��ǡѹ�� ШѴ��ŧ��ź�� ¨ж١��ҹ��ѹ�Ѻ�ش��з��

��ǹ��С�ȵ��ǹ��ҧ (Global declarations statement)

��ǹ��㹡�û�С�ȵ��Ϳѧ��ѹ��ͧ�� ·ء� ��ǹ�ͧ��ö��¡��ŷ��С��ǹ��

��ǹ�ѧ��ѹ��ѡ (Function main)

��ǹ��ء��е�ͧ�� 㹿ѧ��ѹ��ѡ�л�Сͺ��¤��觵�ҧ� ��ӧҹ �ѧ��ѹ��鹡�÷ӧҹ��¿ѧ��ѹ main() ��ǹ��觵�ҧ� �е�ͧ��¹��ҧ��ͧ�� { �� } �� Ф��觷ء��ҫըе�ͧ�Դ��´��ͧ�� ; (semicolon) ��

��ǹ�ѧ��ѹ��˹��ͧ (User-defined function)

�繡��¹��пѧ��ѹ��ҧ� �� µ�ͧ��ͧ�� { } ��е�ͧ��ҧ�ѧ��ѹ��ͤ��ӧҹ��ҵ�ͧ��Ѻ��ö��¡��

��ǹ͸Ժ�� (Program Comment)

�� (comment) ��ǹ��˵آͧ�� ¹��ͤ��͸Ժ�¡ӡѺŧ�� source code ��觤��ӡ��ż��ǹ��繤��

��ҫ�� 2 Ẻ��

��Ẻ��÷Ѵ�� ��ͧ�� //
��Ẻ��º�÷Ѵ ��ͧ�� /* �� */

��ҧ��ä��ҫ�

1	//Comment only one line
2
3	#include <stdio.h>
4
5	int main()
6	{
7	/*Comment
8	many
9	line*/
10	}

��á�ͧ�ѹ

1	//MyFirstProgram.c
2
3	#include <stdio.h>
4
5	int main()
6	{
7	clrscr();
8	printf("Hello World !\n");
9	getch();
10	}

��Ѿ��

Hello World !

��˵�

��¶֧ ��顴�� Enter ��鹾��

͸Ժ��

��÷Ѵ�� 1:	��ǹ��˵�Ẻ��÷Ѵ��Ǣͧ�� Һ�� MyFirstProgram.c
��÷Ѵ�� 3:	�繡�ú͡��δ�� stdio.h ��㹡��żŴ�� stdio ��Ҩҡ standard input/output �� .h �� ʡ�Ţͧ�δ��ҫ� (h ��Ҩҡ header) �� stdio.h �� δ��ҡ�û�С�� (declaration) �ͧ�ѧ��ѹ�ҵðҹ�ͧ��ҫշ��ǡѺ��èѴ��ô�ҹ�Թ�ص��ҵ�ص��¡ѹ��ա��¡��ҹ�ѧ��ѹ printf() ��ʴ��͡�ҧ��Ҿ ��ͧ�ҡ��ǹ�ͧ��û�С�ȿѧ��ѹ printf() �١��è��δ�� stdio.h �ѧ��鹨֧��繵�ͧ��δ�� stdio.h ��㹡��żŴ��
��÷Ѵ�� 5:	��Ϳѧ��ѹ main() ��繿ѧ��ѹ��ѡ�ͧ�� ÷ӧҹ�ͧ��ҫը��鹷��ѧ��ѹ��
��÷Ѵ�� 6:	��ͧ�� { �кبش��鹢ͧ�ѧ��ѹ main()
��÷Ѵ�� 7:	�繤��˹�Ҩ��ʴ��Ѿ��
��÷Ѵ�� 8:	�繡��¡��ѧ��ѹ printf() ��繿ѧ��ѹ�ҵðҹ�ͧ��ҫշ�˹�ҷ��ʴ��Ţ��͡�ҧ��Ҿ 㹷��ʴ��ͤ�� Hello World ! �͡�ҧ��Ҿ
��÷Ѵ�� 9:	�繡��¡��ѧ��ѹ getch() ��繿ѧ��ѹ�ҵðҹ�ͧ��ҫշ�˹�ҷ��Ѻ��ѡ�� ͡�ҡ˹�ҨͻѨ�غѹ
��÷Ѵ�� 10:	��ͧ�� } �кبش��ش�ͧ�ѧ��ѹ main()

/ / เป็นสัญลักษณ์ของการเขียนอธิบายโปรแกรมแบบใด คำสั่ง printf

คำสั่ง การประมวลผลก่อน