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
Explain
D supports imperative, object-oriented, and functional programming paradigms.
It offers safe systems-level programming with modern abstractions.
Templates, mixins, and compile-time reflection enable advanced metaprogramming.
Core Features
Strong static typing with type inference
Modules and package system
Function overloading, operator overloading
First-class functions and closures
Compile-time reflection and code generation
Basic Concepts Overview
Variables, constants, and types
Functions and procedures
Control flow: if, while, for, switch
Structs, classes, and interfaces
Modules, packages, and imports
Project Structure
src/ - D source files
tests/ - unit and integration tests
dub.json - project configuration and dependencies
examples/ - sample programs
docs/ - project documentation
Building Workflow
Write source code (.d files)
Compile using dmd, ldc, or gdc
Use Dub for dependencies and builds
Run unit tests with built-in test blocks
Deploy native binaries across platforms
Difficulty Use Cases
Beginner: basic scripts, control flow, functions
Intermediate: classes, templates, operator overloading
Advanced: compile-time reflection, mixins, ranges
Expert: game engines, high-performance computing, concurrency
Research: DSLs, metaprogramming, compiler extensions
Comparisons
Similar performance to C++
Higher-level features than C/C++
Easier syntax than C++ templates
Smaller ecosystem than Rust or Go
Better compile-time metaprogramming than most mainstream languages
Versioning Timeline
1999 - D initial design by Walter Bright
2001 - D1 language released
2007 - D2 language released with modern features
2010s - Growth of ecosystem and community
2020s - Active development and library expansion
Glossary
Struct: value-type user-defined type
Class: reference-type user-defined type
Template: generic code construct
Mixin: compile-time code insertion
Range: iterable sequence abstraction
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.