Small C pointer memo

pointer_memo.md

Small C pointer syntax memo

Code

int a = 5;
int *b = &a;
int **c = &b;
int ***e = &c;

void func(int d)
{
	d++;
}

func(a) // a will stay the same, func will just copy it in d, 
	// increment it and garbage collect it after exiting

Memory layout

Address	0	1	2	3	4
Variable	b	d	a	e	c
Value	2	6	5	4	0
Content	&a	6	5	&c	&b

Note: d is garbage collected after exiting func. Addressing is arbitrary and is just given as an example.

Pointer and addresses recap

As a rule of thumb, balance asterisks: when the variable gains an asterisk, the type loses one, and vice-versa. Ampersands add asterisks.

Variable	Type
a	int
b	int*
c	int**
e	int***
*b	int
*c	int*
**c	int
*e	int**
**e	int*
***e	int
&a	int*
&b	int**
&c	int***
&e	int****