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.