Sample C Program

/*Program to add three numbers and calculate   them average*/

 #include<stdio.h>

 #include<conio.h>

 void main()

 {
  //first we declare of variable

  int n1=10;

  int n2=20;

  int n3=30;

  int sum,avg;

  clrscr();

    sum=n1+n2+n3;

    avg=sum/3;

    printf("\nSum Of Threes numbers is %d",sum);

    printf("\nAverage of  n1,n2,n3=%d",avg);

 }

 Output of the above program : 

 Sum Of Threes numbers is 60

 Average of n1,n2,n3=20

Let's discuss some useful tips of above program :

• In C language there are two types of comments written as :
  1. Single line comment:single line comment give by two forward slash (//).Example : // this is single line comment
  2. Multi line comment: Multi line comment give by this form : /* it is a multi line comment and its can be spilt into several lines.*/
• Comments can't be nested.
• main() is a function and gives to a set of statement. If a function is void then it is nothing return otherwise its always return value.
• Any variable used in the program must be declared before using it.
• printf() function: It is used to print the value at console. The syntax of printf() as following:                                     printf("<format string>",<variable name>);                   
  

  format string can be following type:

  %d=printing integer values

  %f=printing real values

  %c=printing character values

•   "\n" is one of the several escape sequence in C.It is force to cursour go to next line.