C/Pointers with words
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Revision as of 19:51, 12 March 2012
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.
