Everything you need to know about pointers in C

Abstraction: Comprehensive C pointer tutorial covering declaration through function pointers

Key points:

• A pointer is a memory address; dereferencing with * reads/writes the value at that address; & yields the address of a variable
• Common pitfall: int* ptr_a, ptr_b declares only ptr_a as a pointer; ptr_b is a plain int because the asterisk is per-variable, not per-type
• Arrays decay to pointers to their first element in most contexts; sizeof(array) is the exception that returns total array size
• Subscript operator [] is purely pointer arithmetic: array[i] is identical to *(array + i), scaled by sizeof(type)
• Function pointer declaration syntax: char (strcpy_ptr)(char dst, const char src); typedefs are recommended to reduce complexity
• Strings in C are null-terminated char arrays with no native string type; all string.h functions operate on char pointers

Connections: C Programming · Memory Management · Pointers

Source: http://boredzo.org/pointers/