Integer Types

Vaibhav • September 11, 2025

In the previous article, we introduced the concept of data types and explained why C# uses strong typing to ensure safety and clarity. Now we begin our deep dive into specific types-starting with integers. Integers are the backbone of most programs: they count things, track positions, store IDs, and much more. In this article, we’ll explore the four primary integer types in C#: int, long, short, and byte. We’ll look at their ranges, memory sizes, and how to avoid common pitfalls like overflow and underflow.

What Are Integer Types?

Integer types represent whole numbers-no decimal points, no fractions. They’re used when you need to count, index, or store numeric values that don’t require precision beyond whole units. C# provides several integer types, each with a different range and memory footprint. Choosing the right one depends on how large the numbers you expect to store are, and how much memory you want to use.

All integer types in C# are value types. This means they are stored directly in memory (typically on the stack) and hold their actual value-not a reference to it.

Meet the Integer Family

Let’s look at the four most commonly used integer types in C#: 

// Declaration examples
int score = 100;
long population = 7800000000;
short temperature = -10;
byte level = 255;

Each of these types has a specific range and size:

Type Size Range
int 4 bytes -2,147,483,648 to 2,147,483,647
long 8 bytes -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
short 2 bytes -32,768 to 32,767
byte 1 byte 0 to 255

As you can see, int is the default choice for most whole numbers. It offers a wide enough range for everyday use and is efficient in terms of performance. long is used when you need to store very large numbers-like timestamps or global population counts. short and byte are useful when memory is tight or when you’re working with constrained data (like sensor readings or pixel values).

C# also provides unsigned versions of these types-uint, ulong, ushort, and byte (already unsigned). These allow only positive values and extend the upper range.

How Memory Size Affects Performance

The size of an integer type affects both memory usage and performance. Smaller types like byte and short use less memory, which can be important in large arrays or embedded systems. However, modern CPUs are optimized for 32-bit and 64-bit operations, so using int or long is often faster than using smaller types.

For example, if you’re storing a list of ages, byte might be sufficient (since ages are between 0 and 120). But if you’re doing arithmetic or comparisons, int might be more efficient.

Use int by default unless you have a specific reason to use a smaller or larger type. It balances range, performance, and readability.

Overflow and Underflow

One of the most important things to understand about integer types is that they have fixed ranges. If you try to store a number outside that range, you’ll encounter overflow or underflow. 

// Overflow example
byte level = 255;
level++; // Wraps around to 0

// Underflow example
short temperature = -32768;
temperature--; // Wraps around to 32767

In C#, overflow and underflow don’t throw errors by default. Instead, the value wraps around-like a clock going from 12 to 1. This can lead to subtle bugs if you’re not careful.

You can enable overflow checking using the checked keyword. This forces C# to throw an exception if a value exceeds its range. 

// Checked block
checked
{
    byte level = 255;
    level++; // Throws OverflowException
}

This is especially useful in financial or scientific applications where accuracy matters. You can also enable overflow checking globally in your project settings.

Integer Literals and Readability

When writing integer values in code, you can use underscores to improve readability. This is helpful for large numbers like IDs or timestamps. 

// Readable literals
int population = 7_800_000_000;
long timestamp = 1_638_000_000_000;

These underscores are ignored by the compiler but make your code easier to read and maintain.

Choosing the Right Type

Picking the right integer type is a balance between range, memory, and clarity. Here are some guidelines:

  • Use int for general-purpose whole numbers.
  • Use long for large values like timestamps or file sizes.
  • Use short or byte for constrained data or memory-sensitive scenarios.
  • Use checked when overflow must be detected.

Remember, clarity matters. Don’t use byte just to save a few bytes if it makes your code harder to understand.

Integer Operations

You can perform arithmetic operations on integers just like you’d expect: addition, subtraction, multiplication, division, and modulus. These operations follow standard math rules and operator precedence. 

// Arithmetic operations
int a = 10;
int b = 3;
int sum = a + b;       // 13
int diff = a - b;      // 7
int product = a * b;   // 30
int quotient = a / b;  // 3
int remainder = a % b; // 1

Division between integers always results in an integer. If you want a decimal result, you’ll need to use floating-point types (covered in the next article).

Summary

Integer types are essential for counting, indexing, and storing whole numbers in your programs. C# provides several options-int, long, short, and byte-each with its own range and memory size. Understanding these types helps you write efficient, safe, and readable code.

In this article, you learned:

  • What integer types are and why they matter
  • The ranges and sizes of int, long, short, and byte
  • How to avoid overflow and underflow
  • How to choose the right type for your scenario
  • How integer operations behave in C#

In the next article, we’ll explore Floating-Point Numbers-how to work with decimals, understand precision, and avoid common pitfalls in financial and scientific calculations.