Programming in C · topic
Address and indirection operators, pointer arithmetic and comparisons, void pointers and null pointers, pointers to pointers, const placement, function pointers, reading declarations, malloc, calloc, realloc and free, leaks, double free, dangling and wild pointers, and linked structures.
The address and indirection operators, declarators such as int *p, q, a memory snapshot of an array, a pointer and a pointer to pointer, pointer arithmetic scaled by the element size, pointer subtraction and comparison rules, one past the end, the *p++ family traced on an array, const placement with its compile errors, and null, wild and dangling pointers.
A partial preview of the top of the sheet. The full sheet is in the Programming in C cheat sheet pack.
![int a[4] = {10, 20, 30, 40} at addresses 1000 to 1012; pointer p at 2000 holds 1004 and points to a[1]; pointer pp at 3000 holds 2000 and points to p.](https://bywjbbkinjqiyalvzqfd.supabase.co/storage/v1/object/public/sheet-media/PCC/PCC-13/diagrams/PCC-13.d01.webp)
Rules for void pointers (implicit conversion, no dereference, no arithmetic in ISO C), the null pointer constant, function pointers (declaration, assignment, two call forms, arrays of function pointers, callbacks and a qsort comparator), typedef for function pointer types, and the inside-out method for reading declarations such as int (*a)[10], int *f(int) and int (*(*f)(int))[3].
A partial preview of the top of the sheet. The full sheet is in the Programming in C cheat sheet pack.
malloc, calloc, realloc and free with their return values, the safe realloc idiom, memory leaks, double free, use after free, dangling pointers from returning a local and wild pointers, which defects are undefined behaviour, self-referential structures, inserting at the head of a linked list with a diagram, unlinking a node in the right order, reversing a list, and freeing a whole list.
A partial preview of the top of the sheet. The full sheet is in the Programming in C cheat sheet pack.
