Category: C Programming

Use the preprocessor for includes, macros, and conditional compilation.

Allocate zero-initialized memory with calloc.

Resize previously allocated blocks with realloc.

Release heap memory with free.

Control lifetime and linkage with auto, static, extern, and register.

Know auto as the default for local variables (rarely written explicitly).

Use static for persistent locals and internal linkage at file scope.

Declare variables/functions defined elsewhere with extern.

Allocate heap memory at runtime and free it when done.

Allocate uninitialized bytes with malloc.