== Program 1 == (Basic knowledge of C programming)
#include <stdio.h>
main()

{	int input;
	
	printf("Please input a integer : ");
	scanf("%d",&input);
	printf("The number that you input is %d.",input);
}
== Output == (suppose your input is '1')
Please input a integer : 1
The number that you input is 1.
----------------------------------------
== Program 2 == (Basic program of character)
#include <stdio.h>
main()

{	char a,b,c;

	printf("Please input your name : ");
	scanf("%c%c%c",&a,&b,&c);
	printf("Your name is %c%c%c.",a,b,c);
}
== Output == (suppose your input is 'Joe')
Please input your name : Joe
Your name is Joe.
----------------------------------------
== Program 3 == (Basic program of string)
#include <stdio.h>
main()

{	char input[10];

	printf("Please input your name : ");
	gets(input);
	printf("Your name is %s.",input);
}
== Output == (suppose your input is 'Patrick')
Please input your name : Patrick
Your name is Patrick.
----------------------------------------
== Program 4 == (Basic program of Maths. function)
#include <stdio.h>
#include <math.h>
main()

{	double a=10,b=4,c=10,d=-10,e=1.2,f=1.8;

	a = pow(a,2)
	printf("%lf\n",a);
	b = sqrt(b);
	printf("%lf\n",b);
	c = log(c);
	printf("%lf\n",c);
	d = abs(d);
	printf("%lf\n",d);
	e = floor(e);
	printf("%lf\n",e);
	f = ceil(f);
	printf("%lf\n",f);
}
== Output ==
100
2
1
10
1
2
----------------------------------------
== Program 5 == (if..else)
#include <stdio.h>
main()

{	int input;

	printf("Please input your marks : ");
	scanf("%d",&input);
	if (input>=40)
	  printf("You pass.");
	else
          printf("You fail.");
}
== Output == (suppose you input '50')
Please input your marks : 50
You pass.
----------------------------------------
== Program 6 == (while looping)
#include <stdio.h>
main()

{	int count=0;
	char name[10];

	printf("How many name you want to input? : ");
	scanf("%d",&count);
	while (count!=0)
	{  printf("Input your name : ");
	   gets(name);
	   printf("%s\n",name);
	   count = count-1;
	}
}
== Output == (suppose your input '2' names)
How many name you want to input? : 2
Input your name : Bill
Bill
Input your name : Gates
Gates
----------------------------------------
== Program 7 == (use of string)
#include <stdio.h>
main()

{	char name[50];
	char test[50];
	int count=0;
	
	printf("Please input your name : ");
	gets(name);
	count = strlen(name);
	printf("Your input contains %d character(s).",count);
	if (strcmp(name,"Alan")==0)
	  printf("You are Alan.");
	else
	  printf("You are not Alan.");
	strcat(name," is the great.");
	strcpy(test,name);
	printf("%s",name);
	printf("%s",test);
}
== Output == (suppose you input 'Alan')
Please input your name : Alan
Your input contains 4 characters(s).
You are Alan.
Alan is the great.
Alan is the great.