In Java, integer types are used to store whole numbers (without a decimal part). They are always stored in Base-2 (binary) format, because computers understand only binary digits (0 and 1).

Java represents integers using the 2’s complement system, which allows both positive and negative numbers to be stored efficiently.

1. byte

byte a;

2. short

short a;

3. int

int a;

4. long

long a;

long bigValue = 2147483648L; // ✅ Correct
long wrongValue = 2147483648; // ❌ Error (out of int range)

Bonus Point : BigInteger (Class)

• Package: java.math.BigInteger
• Purpose: Used when integer values go beyond the range of all primitive integer types, including long.
• Size: No fixed size (limited only by available memory).
• Operations Supported: Addition, subtraction, multiplication, division, power, modulus, GCD, etc.
• Usage: Required for cryptography, scientific calculations, or extremely large numbers.

import java.math.BigInteger;

public class BigIntegerExample {
    public static void main(String[] args) {
        // very large numbers (greater than long)
        BigInteger num1 = new BigInteger("92233720368547758070");
        BigInteger num2 = new BigInteger("12345678901234567890");

        // arithmetic operations
        BigInteger sum = num1.add(num2);
        BigInteger product = num1.multiply(num2);

        System.out.println("Sum = " + sum);
        System.out.println("Product = " + product);
    }
}

Why Do We Have Different Integer Data Types in Java?

Java provides multiple integer types (byte, short, int, long) for flexibility and efficiency

1. Memory Efficiency – Smaller types (byte, short) save memory, especially in large arrays.
2. Range Requirements – Different types cover different ranges of values (from small numbers to very large).
3. Performance – JVM can optimize arithmetic with appropriate types.
4. Code Clarity – Using the right type makes the code more meaningful (e.g., byte age, long population).
5. Application Needs – Each type suits different use cases (e.g., byte in file handling, long in big calculations).

In short: Different integer types exist to balance memory, performance, range, and clarity.

Summary: