Examples

1.c program print string

This program print a string. String can be printed by using various functions such as printf, puts.

C programming code

#include<stdio.h>
 
int main()
{
    char array[20] = "Hello World";
 
    printf("%s\n",array);
 
    return 0;
}

To input a string we use scanf function.

C programming code

#include<stdio.h>
 
int main()
{
    char array[100];
 
    printf("Enter a string\n");
    scanf("%s",&array);
 
    printf("You entered the string %s\n",array);
    return 0;
}

Note that scanf can only input single word strings, to receive strings containing spaces use gets function.

2.c program to add two numbers

C program to add two numbers: This c language program perform the basic arithmetic operation of addition on two numbers and then prints the sum on the screen. For example if the user entered two numbers as 5, 6 then 11 ( 5 + 6 ) will be printed on the screen.

C programming code

#include<stdio.h>
 
int main()
{
   int a, b, c;
 
   printf("Enter two numbers to add\n");
   scanf("%d%d",&a,&b);
 
   c = a + b;
 
   printf("Sum of entered numbers = %d\n",c);
 
   return 0;
}

Add numbers program executable.

Output of program

Addition without using third variable

#include<stdio.h>
 
int main()
{
   int a = 1, b = 2;
 
   /* Storing result of addition in variable a */
 
   a = a + b;
 
   /* Not recommended because original value of a is lost  
    * and you may be using it some where in code considering it 
    * as it was entered by the user. 
    */
 
   printf("Sum of a and b = %d\n", a);
 
   return 0;
}

C program to add two numbers repeatedly

#include<stdio.h>
 
int main()
{
   int a, b, c;
   char ch;
 
   while(1)
   {
      printf("Enter values of a and b\n");
      scanf("%d%d",&a,&b);
 
      c = a + b;
 
      printf("a + b = %d\n", c);
 
      printf("Do you wish to add more numbers(y/n)\n");
      scanf(" %c",&ch);
 
      if ( ch == 'y' || ch == 'Y' )
         continue;
      else
     break;
   }
 
   return 0;
}

Adding numbers in c using function

We have used long data type as it can handle large numbers.

#include<stdio.h>
 
long addition(long, long);
 
int main()
{
   long first, second, sum;
 
   scanf("%ld%ld", &first, &second);
 
   sum = addition(first, second);
 
   printf("%ld\n", sum);
 
   return 0;
}
 
long addition(long a, long b)
{
   long result;
 
   result = a + b;
 
   return result;
}