General Programming Cheatsheet

TODO: There isn’t a lot of content here yet since I’m only filling it out as I need it.

Fixed-Width Integers

This table assumes you’re programming in C on a common computer architecture. “Minimum C Type” refers to C type in which the language specification requires this size to be the minimum. To keep it simple, I only include an easily recognizable subset.

Description	Minimum			Maximum			Minimum C Type
Unsigned 8-bit (1 bytes)	`0`			`255`	$2^{8} - 1$	$> 2 \times {10}^{2}$	`unsigned char`
Unsigned 16-bit (2 bytes)	`0`			`65535`	$2^{16} - 1$	$> 6 \times {10}^{4}$	`unsigned short \| unsigned int`
Unsigned 32-bit (4 bytes)	`0`			`4294967295`	$2^{32} - 1$	$> 4 \times {10}^{9}$	`unsigned long`
Unsigned 64-bit (8 bytes)	`0`			`18446744073709551615`	$2^{64} - 1$	$> 1 \times {10}^{19}$	`unsigned long long`
Signed 8-bit (1 bytes)	`-128`	$-2^{7}$	$< -1 \times {10}^{2}$	`127`	$2^{7} - 1$	$> 1 \times {10}^{2}$	`signed char`
Signed 16-bit (2 bytes)	`-32768`	$-2^{15}$	$< -3 \times {10}^{4}$	`32767`	$2^{15} - 1$	$> 3 \times {10}^{4}$	`short \| int`
Signed 32-bit (4 bytes)	`-2147483648`	$-2^{31}$	$< -2 \times {10}^{9}$	`2147483647`	$2^{31} - 1$	$> 2 \times {10}^{9}$	`long`
Signed 64-bit (8 bytes)	`-9223372036854775808`	$-2^{63}$	$< -9 \times {10}^{18}$	`9223372036854775807`	$2^{63} - 1$	$> 9 \times {10}^{18}$	`long long`

Units

Common Name	IEC Name	Bytes
kilobyte (kB)	kibibyte (KiB)	${1024}^1$	`1024`
megabyte (MB)	mebibyte (MiB)	${1024}^2$	`1048576`
gigabyte (GB)	gibibyte (GiB)	${1024}^3$	`1073741824`
terabyte (TB)	tebibyte (TiB)	${1024}^4$	`1099511627776`
petabyte (PB)	pebibyte (PiB)	${1024}^5$	`1125899906842624`
See Wikipedia for larger units.

$2^{0}$	`1`
$2^{1}$	`2`
$2^{2}$	`4`
$2^{3}$	`8`
$2^{4}$	`16`
$2^{5}$	`32`
$2^{6}$	`64`
$2^{7}$	`128`
$2^{8}$	`256`
$2^{9}$	`512`
$2^{10}$	`1024`
$2 \times 1024$	`2048`
$4 \times 1024$	`4096`
$8 \times 1024$	`8192`
$16 \times 1024$	`16384`
$32 \times 1024$	`32768`
$64 \times 1024$	`65536`