Java Program to Find the Largest of Three Numbers

📘 Premium Read: Access my best content on Medium member-only articles — deep dives into Java, Spring Boot, Microservices, backend architecture, interview preparation, career advice, and industry-standard best practices.

🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.

▶️ Subscribe to My YouTube Channel (176K+ subscribers): Java Guides on YouTube

▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube

Introduction

Finding the largest of three numbers is a basic programming task often used to practice conditional statements and logical comparisons. This guide will show you how to create a Java program that takes three numbers as input and determines the largest among them.

Problem Statement

Create a Java program that:

• Takes three integer inputs from the user.
• Compares the three numbers.
• Returns and displays the largest number.

Example 1:

• Input: 3, 5, 7
• Output: The largest number is 7

Example 2:

• Input: 10, 20, 15
• Output: The largest number is 20

Example 3:

• Input: 25, 25, 25
• Output: The largest number is 25 (all are equal)

Solution Steps

1. Prompt for Input: Use the Scanner class to read three integer inputs from the user.
2. Compare the Numbers Using Conditional Statements: Use if-else or ternary operator to compare the three numbers and determine the largest.
3. Display the Result: Print the largest number.

Java Program

Approach 1: Using if-else Statements

import java.util.Scanner; /** * Java Program to Find the Largest of Three Numbers using if-else statements * Author: https://www.javaguides.net/ */ public class LargestOfThree { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); // Step 1: Prompt the user for input System.out.print("Enter the first number: "); int num1 = scanner.nextInt(); System.out.print("Enter the second number: "); int num2 = scanner.nextInt(); System.out.print("Enter the third number: "); int num3 = scanner.nextInt(); // Step 2: Compare the numbers using if-else statements int largest; if (num1 >= num2 && num1 >= num3) { largest = num1; } else if (num2 >= num1 && num2 >= num3) { largest = num2; } else { largest = num3; } // Step 3: Display the result System.out.println("The largest number is " + largest); } } 

Explanation

• Input: The program prompts the user to enter three numbers.

• Comparison:

  • The if-else statements compare the three numbers to determine which one is the largest.
  • If num1 is greater than or equal to both num2 and num3, then num1 is the largest.
  • Otherwise, if num2 is greater than or equal to both num1 and num3, then num2 is the largest.
  • If neither num1 nor num2 is the largest, then num3 is the largest.

• Output: The program prints the largest number.

Output Example

Example 1:

Enter the first number: 3 Enter the second number: 5 Enter the third number: 7 The largest number is 7 

Example 2:

Enter the first number: 10 Enter the second number: 20 Enter the third number: 15 The largest number is 20 

Example 3:

Enter the first number: 25 Enter the second number: 25 Enter the third number: 25 The largest number is 25 

Approach 2: Using Ternary Operator

import java.util.Scanner; /** * Java Program to Find the Largest of Three Numbers using Ternary Operator * Author: https://www.javaguides.net/ */ public class LargestOfThreeTernary { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); // Step 1: Prompt the user for input System.out.print("Enter the first number: "); int num1 = scanner.nextInt(); System.out.print("Enter the second number: "); int num2 = scanner.nextInt(); System.out.print("Enter the third number: "); int num3 = scanner.nextInt(); // Step 2: Compare the numbers using the ternary operator int largest = (num1 >= num2) ? (num1 >= num3 ? num1 : num3) : (num2 >= num3 ? num2 : num3); // Step 3: Display the result System.out.println("The largest number is " + largest); } } 

Explanation

• Comparison Using Ternary Operator:
  • The ternary operator simplifies the comparison by nesting conditional checks:
    • If num1 is greater than or equal to num2, the program checks whether num1 is also greater than or equal to num3.
    • If not, it compares num2 with num3 to find the largest.

Output Example

The output for the ternary operator approach will be the same as the if-else approach.

Conclusion

This Java program demonstrates how to find the largest of three numbers using both if-else statements and the ternary operator. Both approaches are effective and straightforward, with the ternary operator offering a more concise syntax. This basic problem is a good exercise for practicing conditional statements and can be extended to more complex comparisons if needed.