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.

Limited time offer: Get 10 free Adobe Stock images.ADS VIA CARBON

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

• C Programming Operators
• C if…else Statement

Example 1: Using if Statement

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

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

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

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

    return 0;
}

Example 2: Using if…else Ladder

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

    // if n1 is greater than both n2 and n3, n1 is the largest
    if (n1 >= n2 && n1 >= n3)
        printf("%.2lf is the largest number.", n1);

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

    // if both above conditions are false, n3 is the largest
    else
        printf("%.2lf is the largest number.", n3);

    return 0;
}

Example 3: Using Nested if…else

#include 
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.