C Program to Find Largest Among 3 Numbers

To find the largest among 3 numbers entered by the user in C programming, nested if can be used which is implemented in following program:

Example 1: Source Code to Find Largest Number Using nested if..else Statement

#include<stdio.h>
int main()
{
   int a,b,c;
   printf ("Enter three numbers \n");
   scanf("%d \n %d \n %d",&a, &b, &c);

   if (a>b)
   {
        if(a>c)
            printf("%d is the largest number.",a);
        else
            printf("%d is the largest number.",c);
   }
    else
    {
        if(b>c)
           printf("%d is the largest number.",b);
        else
           printf("%d is the largest number.",c);
   }

   return 0;
}

Here, the 3 numbers given by user is stored in variables a, b and c respectively. The first if statement checks if a>b, if it is true then second if statement is checked i.e. a>c, if this is also true then a is the largest among the three. If the second if condition is false (i.e. if a is not greater than c) then c is the largest among the three. However, if the first if condition is false (i.e. if a is not greater than b) then the condition b>c is checked, if this is true then b is the largest among the three and if this is false then c is the largest.

Example 2: Source Code to Find Largest Number Using if..else Statement

#include<stdio.h>
#include<conio.h>

int main()
{

    int a,b,c;
    printf ("Enter three numbers \n");
    scanf ("%d \n %d \n %d", &a, &b, &c);

    if (a>b && a>c)
       printf ("%d is the largest number.", a);
    else if (b>a && b>c)
      printf ("%d is the largest number.", b);
    else
      printf ("%d is the largest number.", c);

    return 0;
}


Here, the statement if (a>b && a>c) checks whether a is greater than both b and c and if it is true then displays “a is the largest”. If it is false then the second condition is checked. If the second statement is true then b is the largest is displayed and if this condition is also false then c is the largest is displayed.

Output

Enter three numbers
12
40
10
40 is the largest.