Learn C, one working program at a time
Understand the code you run. These guides connect C fundamentals with small experiments, common mistakes, and practical ways to test your understanding in Circuit’s online C compiler.
New to C? Start with your first program, then input, arrays, and functions. The compiler guides explain what happens between pressing Run and seeing a result.
How to Write and Run Your First C Program
Write a first C program, understand main and printf, and test it in Circuit’s online C compiler while saving your work locally.
Read guide →Guide 02How a C Compiler Works
Understand how a C compiler reads source, checks types, generates code, and works with a linker and runtime, including Circuit’s browser-based approach.
Read guide →Guide 03C Compilation Process Explained
Follow preprocessing, compilation, assembly, linking, and execution, with practical GCC stage commands and Circuit differences.
Read guide →Guide 04printf() and scanf() in C
Use formatted output and interactive input correctly, check scanf results, and avoid common whitespace and buffer mistakes.
Read guide →Guide 05Arrays in C
Learn array bounds, iteration, length, function parameters, strings, and multidimensional arrays through small C examples.
Read guide →Guide 06Functions in C
Define C functions with clear parameters, return values, scope, pointer contracts, and small tests.
Read guide →Guide 07Pointers in C for Beginners
Understand addresses, dereferencing, pointer lifetime, arrays, const, and safe pointer-based updates in C.
Read guide →Guide 08Common C Compiler Errors and How to Fix Them
Diagnose missing punctuation, declarations, format mismatches, linker errors, and warnings without guessing at random changes.
Read guide →Guide 09What Causes a Segmentation Fault in C?
Understand invalid memory access, array bounds, dangling pointers, stack exhaustion, and how browser WebAssembly failures differ.
Read guide →Guide 10Compiler vs Interpreter
Compare translation and execution strategies without assuming every language is exclusively compiled or interpreted.
Read guide →Guide 11Online C Compiler vs Installing GCC
Compare Circuit’s online C compiler with a desktop GCC toolchain based on setup, files, debugging, portability, and system access.
Read guide →Guide 12Basic C Program Examples
Build a learning sequence from greetings and conditions to loops, arrays, functions, pointers, and structures with testable C examples.
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