Uses for Unsigned Integers

If unsigned integers are problematic, why do they exist at all? Are there any real-world cases where they're useful?

While unsigned integers can be tricky to work with, they do have legitimate uses. Here are some real-world scenarios where unsigned integers make sense:

Array Sizes and Counts

When you're counting things or working with sizes, the number can never be negative. For example, you can't have -3 players in a game. However, we typically still use regular integers for these because the benefits rarely outweigh the risks.

Hardware and Low-Level Programming

When working directly with computer hardware, unsigned integers are often required because they map directly to how the hardware works. For example, memory addresses are always positive numbers.

Binary Data and File Sizes

When working with file sizes or network data, unsigned integers are commonly used because these values are never negative:

#include <iostream>
using namespace std;

int main() {
  // File sizes are never negative
  uint64_t VideoFileSize{1'500'000'000};

  // Data amounts are never negative
  uint32_t BytesDownloaded{750'000};

  cout << "Downloading " << BytesDownloaded
    << " bytes out of " << VideoFileSize;

  // This would make no sense - a file
  // can't be -1000 bytes!
  int NegativeFileSize{-1'000};  
}
Downloading 750000 bytes out of 1500000000

Bitwise Operations

When doing binary operations (working directly with bits), unsigned integers are often preferred because they have well-defined behavior:

#include <iostream>
using namespace std;

int main() {
  // Using binary literal
  uint8_t Flags{0b00000101};

  // Each bit can represent a yes/no setting
  // First bit
  bool IsHappy = (Flags & 0b00000001) != 0;

    // Third bit
  bool IsFlying = (Flags & 0b00000100) != 0;

  cout << "Character is happy: " << IsHappy
    << "\nCharacter is flying: " << IsFlying;
}
Character is happy: 1
Character is flying: 1

However, unless you're doing one of these specialized tasks, it's usually better to use regular signed integers. They're safer because:

  • You can't accidentally go below zero
  • They work more intuitively with subtraction
  • They cause fewer surprises when mixed with regular integers
  • Most C++ standard library functions expect signed integers

The general rule is: use signed integers by default, and only use unsigned integers when you have a specific reason to do so and understand the implications.

Types and Literals

Explore how C++ programs store and manage numbers in computer memory, including integer and floating-point types, memory allocation, and overflow handling.

Questions & Answers

Answers are generated by AI models and may not have been reviewed. Be mindful when running any code on your device.

Memory Usage in Modern Computers
Why do we need to care about memory usage in modern computers when they have so much RAM available?
How Computers Store Text
In the Memory section, you mention bits can be used to represent characters. How can 0s and 1s represent letters?
Monitoring Program Memory Usage
How can I know how much memory my entire program is using? Is there a way to check this?
When to Use Small Integer Types
In the real world, when would I choose to use a smaller integer type like int8_t instead of just using regular int?
Preventing Number Overflow
How can I check if my number will cause an overflow before performing a calculation?
Controlling Decimal Places
When I print floating point numbers, they sometimes show way more decimal places than I want. How can I control this?
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