Learn D - 10 Code Examples & CST Typing Practice Test
D is a high-level, statically typed, compiled systems programming language combining C-like performance with modern features like garbage collection, functional programming, and meta-programming.
Learn D with Real Code Examples
Updated Nov 20, 2025
Practical Examples
Hello world CLI
Range-based iteration example
Template function for generic containers
Class with inheritance and interfaces
Compile-time mixin code generation
Troubleshooting
Resolve type mismatches
Check template constraints
Ensure correct module imports
Fix memory management issues
Verify compile-time mixin syntax
Testing Guide
Use built-in unittest blocks
Check contracts for invariants
Test template-generated code
Validate concurrency and async code
Profile performance and memory usage
Deployment Options
Native binaries for Linux, Windows, macOS
Dockerized deployment for web backends
Game engine executables
Financial and scientific applications
Cross-platform CLI tools
Tools Ecosystem
DMD, LDC, GDC compilers
Dub package manager
Vibe.d for web backends
Derelict for C interop
Phobos standard library
Integrations
Interop with C and C++
Web frameworks like Vibe.d
Scientific libraries for numerical computing
Game engine development
Compile-time metaprogramming and DSLs
Productivity Tips
Use Dub for project and dependency management
Write unittest blocks early
Profile and optimize code iteratively
Use templates/mixins for repetitive patterns
Organize code with modules/packages
Challenges
Build CLI calculator
Implement generic container using templates
Create a web server with Vibe.d
Develop high-performance numeric application
Use compile-time mixins for repetitive code
Frequently Asked Questions about D
What is D?
D is a high-level, statically typed, compiled systems programming language combining C-like performance with modern features like garbage collection, functional programming, and meta-programming.
What are the primary use cases for D?
Systems programming and OS-level development. High-performance computing. Game engines and graphics programming. Financial and trading applications. Compile-time code generation and metaprogramming
What are the strengths of D?
High-performance native code. Clean modern syntax with C-style familiarity. Powerful compile-time metaprogramming. Versatile multi-paradigm language. Rich standard library with ranges and algorithms
What are the limitations of D?
Smaller community and ecosystem than C++ or Rust. Less industrial adoption for large-scale projects. Limited GUI library support. Garbage collector can be unpredictable in real-time systems. Interfacing with C++ can be complex
How can I practice D typing speed?
CodeSpeedTest offers 10+ real D code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.