c program to find the greatest of three numbers

This is the simple program in C language to find the greatest of three numbers with the help of else if, this program is based on a functional approach.


  1. Take input three numbers from user.
  2. Call function with these three parameters.
  3. Perform a condition to find greatest number by function.
  4. Retrun the greatest number.
  5. Hold the greatest return value by function.
  6. Print the greatest number of the three numbers.

Source code:

// c program to find the greatest of three numbers

#include <stdio.h>

//fucntion to check greatest among three number
int greatest(int num1, int num2, int num3){
    if(num1>num2 && num1>num3){
        return num1;
    else if(num2>num1 && num2>num3){
        return num2;
        return num3;

//driver function 
int main(){
    //define variables used in program
    int num1, num2, num3, max;
    //take input form user
    printf("\n******Greatest Number Finder******");
    printf("\n\nEnter First number:");
    printf("\nEnter second number:");
    printf("\nEnter Third number:");
    //call function and hold return value in max variable
    max = greatest(num1,num2,num3);
    //print the greatest number
    printf("\n\n%d is the greatest number of three numbers.",max);
    return 0;

Input & Output:

******Greatest Number Finder******

Enter First number:1
Enter second number:2
Enter Third number:3

3 is the greatest number of three numbers.
Posted in: C