Lesser Than Operator Example in Java

Introduction

Lesser Than Operator is a classic Java console program that demonstrates the concept with complete source code and sample output. Operators combine values, compare results and update variables — core skills for every Java program.

This tutorial walks through the program line by line, explains how the logic works, and highlights best practices you can apply in your own code.

Definition

Operators in Java are similar to those in C++. However, there is no delete operator due to garbage collection mechanisms in Java, and there are no operations on pointers since Java does not support them. Greater than operator checks if the value on the left side is greater than the value on the right side of the operator.

Syntax

a < b

Lesser Than Operator Example Program

import java.util.Scanner;
class LesserThanOperator{
	public static void main(String[] args){
		Scanner in=new Scanner(System.in);
		System.out.println("Enter any two numbers to check which is smaller: ");
		int num1=in.nextInt();
		int num2=in.nextInt();
		if( num1  < num2 ){
		System.out.println("num1 is smaller");
		}
		else{
		System.out.println("num2 is smaller");
		}
	}
}

Sample Output

Enter any two numbers to check which is smaller:
45
78
num1 is smaller

When to use

Use this lesser than operator example when learning or revising core Java syntax.

How it works

1. Execution begins in the main method — the JVM calls this method when you run the class.

2. import java.util.Scanner; imports a class used later in the program.

3. A Scanner reads typed input from the keyboard (System.in).

4. A println / print call writes text to the console — part of the sample output below.

5. int num1=in.nextInt(); updates a variable used in the calculation or output.

6. int num2=in.nextInt(); updates a variable used in the calculation or output.

7. The if statement runs the nested code only when the condition is true.

8. A println / print call writes text to the console — part of the sample output below.

Best Practices

• Use meaningful variable and class names that describe their purpose.
• Compile and run the program locally — modify values to see how output changes.
• Read compiler errors carefully; they usually point to the exact line to fix.

Common Mistakes

• Copying code without understanding each line — practice by changing one statement at a time.
• Mismatching the public class name and the .java filename.
• Forgetting semicolons at the end of statements.