C++ Handbook

C Language Reference

C Language Reference

C keywords, types, operators, storage classes, qualifiers, and preprocessor building blocks.

How to use this reference page

Use reference pages to confirm names, categories, nearby facilities, and the constraints that matter before writing or reviewing code.

  • Scan the top of the page first to identify the primary types, functions, or algorithm families involved.
  • Use the nearby-page links when your question is really about a companion header, related algorithm family, or broader subsystem.
  • Validate tricky behavior with a small compileable example before relying on memory for details like invalidation, ordering, allocation, or lifetime rules.

C Language Reference

C keywords

Control flow and structure

Types and declarations

Storage and qualifiers

Compile-time and generic features

Fundamental C types

Integer and character types

Floating and special arithmetic types

Common typedef-based standard types

Operators and punctuation

Arithmetic and bitwise

Comparison and logic

Assignment and update

Access and grouping

Cast and address operations

Storage duration and linkage

Preprocessor building blocks

For a more detailed list of macro categories and conditional-compilation patterns, see C preprocessor and macros.

Declarations you should recognize instantly

int *ptr;
int (*fn)(int);
int values[10];
const char *name;
struct Point { int x; int y; };

Practical lookup checklist

Adjacent reference pages

Example in practice

struct Point {
    int x{};
    int y{};
};

int main() {
    Point p{3, 4};
    return p.x < p.y;
}