C/Pointers with words

Having been criticized by my colleagues, I decided to add some words to my Pointers page.

A Variable

If we start by thinking about a standard variable 'i', assuming an x86, 32-bit system - 32-bit (4 byte) address and integer sizes.

int i;

This is just a block of 4 bytes that the compiler promises it will find memory for. In reality this comes from the stack, but that is a detail for another time.

If we now assign 0xDEADBEEF to i and represent the memory visually, we might find the following (the colouring will become apparent later).

int i;
 
i = 0xDEADBEEF;

Address	Value	Note
...
0xBF893E8F	0xDE	i MSB
0xBF893E8E	0xAD	i
0xBF893E8D	0xBE	i
0xBF893E8C	0xEF	i LSB
...

This is very simple. Store a value in some memory.