Int Datatype Example in Java

Introduction

Int Datatype is a classic Java console program that demonstrates the concept with complete source code and sample output. Java primitive types and wrappers behave differently from objects — these examples show declaration, range and conversion.

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

By default, the int data type is a 32-bit signed two’s complement integer, which has a minimum value of -231 and a maximum value of 231-1. In Java SE 8 and later, you can use the int data type to represent an unsigned 32-bit integer, which has a minimum value of 0 and a maximum value of 232-1. Use the Integer class to use int data type as an unsigned integer.

Syntax

int varibale_name = integer_value;

Syntax Example

int gear = 1;

Int Datatype Example Program

class IntDatatype{
	public static void main(String[] args){
		int num1=0;
		int num2=2147483647;
		System.out.println("The smallest Integer value is: "+num1);
		System.out.println("The largest Integer value is: "+num2);
	}
}

Sample Output

The smallest Integer value is: 0
The largest Integer value is: 2147483647

When to use

Use this int datatype 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. int num1=0; updates a variable used in the calculation or output.

3. int num2=2147483647; updates a variable used in the calculation or output.

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

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

6. Compare your console output with the sample output for Int Datatype to confirm the program behaves correctly.

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.