C Program to Find the Largest Number Among Three Numbers

In this example, you will learn to find the largest number among the three numbers entered by the user.

To understand this example, you should have the knowledge of the following C programming topics:


Example 1: Using if Statement

#include <stdio.h>
int main() {
    double n1, n2, n3;
    printf("Enter three different numbers: ");
    scanf("%lf %lf %lf", &n1, &n2, &n3);

    if (n1 >= n2 && n1 >= n3)
        printf("%.2f is the largest number.", n1);
    if (n2 >= n1 && n2 >= n3)
        printf("%.2f is the largest number.", n2);
    if (n3 >= n1 && n3 >= n2)
        printf("%.2f is the largest number.", n3);

    return 0;
}

Example 2: Using if...else Ladder

#include <stdio.h>
int main() {
    double n1, n2, n3;
    printf("Enter three numbers: ");
    scanf("%lf %lf %lf", &n1, &n2, &n3);

    if (n1 >= n2 && n1 >= n3)
        printf("%.2lf is the largest number.", n1);
    else if (n2 >= n1 && n2 >= n3)
        printf("%.2lf is the largest number.", n2);
    else
        printf("%.2lf is the largest number.", n3);

    return 0;
}

Example 3: Using Nested if...else

#include <stdio.h>
int main() {
    double n1, n2, n3;
    printf("Enter three numbers: ");
    scanf("%lf %lf %lf", &n1, &n2, &n3);

    if (n1 >= n2) {
        if (n1 >= n3)
            printf("%.2lf is the largest number.", n1);
        else
            printf("%.2lf is the largest number.", n3);
    } else {
        if (n2 >= n3)
            printf("%.2lf is the largest number.", n2);
        else
            printf("%.2lf is the largest number.", n3);
    }

    return 0;
}

The output of all these programs above will be the same.

Enter three numbers: -4.5
3.9
5.6
5.60 is the largest number.