How this C track works
- gcc in the playground — write a single
main.cwithint main(void)orint main(int argc, char *argv[]); the dev runner compiles withgcc -std=c11 -Walland runs the binary. - Pointers are the core lesson — C gives you direct memory access. Every pointer example here uses safe, defined patterns: initialize before use, check
malloc, callfree, and avoid out-of-bounds access. - Prerequisites — finish JavaScript (functions, variables) and ideally Java or Rust for typed-systems context. C is low-level; prior programming helps.
Multi-file Make/CMake projects, embedded toolchains, and POSIX APIs run locally—lessons simulate patterns with printf where the sandbox is single-file.
Install on your device (macOS, Linux, Windows)
Install a C/C++ compiler (GCC or Clang) for local projects; playground uses g++/gcc.
macOS
- Install Xcode Command Line Tools:
xcode-select --install clang++ --versionandg++ --version(optional via Homebrewbrew install gcc).
Linux
- Debian/Ubuntu:
sudo apt install -y build-essential gdb - Fedora:
sudo dnf groupinstall -y "Development Tools"
Windows
- Install MSVC Build Tools with “Desktop development with C++”, or MSYS2:
pacman -S mingw-w64-x86_64-gcc.
Verify: c++ --version or g++ --version.
Run code on this site (Backend & language playgrounds)
- Clone or open this project locally; copy
.env.exampleto.env. - Ensure
LEARNING_RUNNER_ENABLED=trueandLEARNING_RUNNER_URL=http://127.0.0.1:9999/v1/execute. - Terminal 1:
php artisan serve(orcomposer run devfor Laravel + Vite + runner together). - Terminal 2:
npm run runner— keep it running while you click Run on server.
C is a low-level systems programming language that compiles directly to machine code. It gives you explicit control over memory through pointers, a minimal runtime, and a small standard library—foundations used by operating systems, embedded firmware, and many higher-level languages.
How this track differs from JavaScript and Java
After the JavaScript track, you know dynamic typing and garbage collection. After Java, you know static types and a JVM that manages memory for you. C is statically typed like Java but has no garbage collector—you decide when stack variables die and when heap memory is freed with free.
Unlike browser scripting, C targets kernels, drivers, firmware, databases, and performance libraries. Expect the compiler to be helpful with warnings, but memory safety is largely your responsibility.
What you will learn
- Syntax: variables, types, control flow, functions, and the preprocessor
- Pointers, arrays, strings, pointer arithmetic, and dynamic allocation
- Structs, unions, enums,
const/volatile, and function pointers - File I/O, headers, compilation, debugging, and undefined behavior awareness
- Standard library basics, CLI args, multi-file projects, and interview essentials
Playground setup
This topic uses the server_compiled profile: your code compiles with gcc -std=c11 -Wall as a single main.c file. Use int main(void) and printf for output.
Self-check
- In one sentence, what makes C different from Java regarding memory?
- Why do we recommend prior programming experience before C?
Interview prep
- What is C in one sentence?
A statically typed procedural language that compiles to native machine code and gives programmers explicit control over memory through pointers and manual heap management.
- Why learn C after JavaScript?
JavaScript hides memory and hardware; C teaches what actually happens under managed runtimes—valuable for systems insight and debugging native libraries.