Java supports multiple integer types to represent whole numbers. These types differ in memory size, value range, and performance, allowing developers to choose the right one based on the data requirements.

The most commonly used integer type for general whole number operations.

int age = 25;
int marks = -100;

• Good performance and memory efficiency
• Be careful of overflow for very large values

Used for storing very large whole numbers, such as timestamps or IDs.

long worldPopulation = 8000000000L;  // Note the 'L' suffix

• Stores massive values beyond int range
• Always use L suffix to avoid confusion

A small-range integer, typically used where memory is tight (e.g., embedded systems, large arrays).

short temperature = -200;
short port = 8080;

• Saves memory (2 bytes per value)
• Not ideal for arithmetic or general-purpose values

Used when integer values exceed the range of long. Found in java.math.

import java.math.BigInteger;

BigInteger big = new BigInteger("999999999999999999999");
BigInteger result = big.multiply(BigInteger.valueOf(2));

• No upper limit—perfect for scientific or financial applications
• Slower, and requires method calls (not +, -, etc.)

• Prefer int unless your use case demands larger or smaller types.
• Use long for timestamps, durations, or unique IDs.
• Use BigInteger for extreme numerical precision.
• Avoid short unless optimizing for memory or dealing with legacy APIs.
• Always check for overflow conditions in calculations.

int studentCount = 3000;
long timestamp = System.currentTimeMillis();
BigInteger balance = new BigInteger("123456789012345678901234567890");

Use the smallest appropriate type for clarity and efficiency.