Contents

Programmer Cheat Sheets

Real Programmers know everything on this page by heart. However, Real Programmers also seek to be ~~lazy~~ efficient. There's no need to memorize everything when you can look it up so quickly.

Unlike other ASCII charts on the Web, this one includes High ASCII and Windows-1252 (Unicode) while remaining succinct. Also, this is not an image, so you can copy & paste from it.

ASCII Chart

dec	hex	chr	notes
0	00		`^@` Nul Ctrl+@ = Null (string terminator)
1	01	`☺`	`^A` SOH `☺` Smiley Face Outlined Ctrl+A = Start Of Header
2	02	`☻`	`^B` STx `☻` Smiley Face Solid Ctrl+B = Start of Text
3	03	`♥`	`^C` ETx `&hearts;` Hearts Ctrl+C = End of Text
4	04	`♦`	`^D` EOT `&diams;` Diamonds Ctrl+D = End Of Transmission
5	05	`♣`	`^E` Enq `&clubs;` Clubs Ctrl+E = Enquiry
6	06	`♠`	`^F` Ack `&spades;` Spades Ctrl+F = Acknowledgement
7	07	`•`	`^G` Bel `•` Bullet Ctrl+G = Bell
8	08	`◘`	`^H` BS `◘` Inverse Bullet Ctrl+H = BackSpace
9	09	`○`	`^I` HT `○` Circle Ctrl+I = Horizontal Tab
10	0A	`◙`	`^J` LF `◙` Inverse Circle Ctrl+J = Line Feed
11	0B	`♂`	`^K` VT `♂` Male Ctrl+K = Vertical Tab
12	0C	`♀`	`^L` FF `♀` Female Ctrl+L = Form Feed
13	0D	`♪`	`^M` CR `♪` Eighth Note Ctrl+M = Carriage Return
14	0E	`♫`	`^N` SO `♫` Beamed Eighth Notes Ctrl+N = Shift Out
15	0F	`☼`	`^O` SI `☼` Sun / Compass Ctrl+O = Shift In
16	10	`►`	`^P` DLE `▶` or `►` Triangle Right or Pointer Right Ctrl+P = Data Link Escape
17	11	`◄`	`^Q` XOn `◀` or `◄` Triangle Left or Pointer Left Ctrl+Q = Transmit-On (or Device Control 1)
18	12	`↕`	`^R` DC2 `↕` Up/Down Arrow Ctrl+R = Device Control 2
19	13	`‼`	`^S` XOff `‼` Double Exclamation Point Ctrl+S = Transmit-Off (or Device Control 3)
20	14	`¶`	`^T` DC4 `¶` Paragraph Ctrl+T = Device Control 4
21	15	`§`	`^U` NAk `§` Section Ctrl+U = Negative Acknowledgement
22	16	`▬`	`^V` Syn `▬` Rectangle Ctrl+V = Synchronize
23	17	`↨`	`^W` ETB `↨` Up/Down Arrow With Base Ctrl+W = End of Transmission Block
24	18	`↑`	`^X` Can `↑` `↑` Up Arrow Ctrl+X = Cancel
25	19	`↓`	`^Y` EM `↓` `↓` Down Arrow Ctrl+Y = End of Medium
26	1A	`→`	`^Z` Sub `→` `→` Right Arrow Ctrl+Z = Substitute
27	1B	`←`	`^[` Esc `←` `←` Left Arrow Ctrl+[ = Escape
28	1C	`∟`	`^\` FS `⌙` `∟` Not Ctrl+\ = File Separator
29	1D	`↔`	`^]` GS `↔` `↔` Horizontal Arrows Ctrl+] = Group Separator
30	1E	`▲`	`^^` RS `▲` Triangle Up Ctrl+^ = Record Separator
31	1F	`▼`	`^_` US `▼` Triangle Down Ctrl+_ = Unit Separator

dec	hex	chr
32	20	space
33	21	`!`
34	22	`"` `"` Quotes
35	23	`#`
36	24	`$`
37	25	`%`
38	26	`&` `&` Ampersand
39	27	`'`
40	28	`(`
41	29	`)`
42	2A	`*`
43	2B	`+`
44	2C	`,`
45	2D	`-`
46	2E	`.`
47	2F	`/`
48	30	`0`
49	31	`1`
50	32	`2`
51	33	`3`
52	34	`4`
53	35	`5`
54	36	`6`
55	37	`7`
56	38	`8`
57	39	`9`
58	3A	`:`
59	3B	`;`
60	3C	`<` `<` Less-Than
61	3D	`=`
62	3E	`>` `>` Greater-Than
63	3F	`?`

dec	hex	chr
64	40	`@`
65	41	`A`
66	42	`B`
67	43	`C`
68	44	`D`
69	45	`E`
70	46	`F`
71	47	`G`
72	48	`H`
73	49	`I`
74	4A	`J`
75	4B	`K`
76	4C	`L`
77	4D	`M`
78	4E	`N`
79	4F	`O`
80	50	`P`
81	51	`Q`
82	52	`R`
83	53	`S`
84	54	`T`
85	55	`U`
86	56	`V`
87	57	`W`
88	58	`X`
89	59	`Y`
90	5A	`Z`
91	5B	`[`
92	5C	`\`
93	5D	`]`
94	5E	`^`
95	5F	`_` underline

dec	hex	chr
96	60	`
97	61	`a`
98	62	`b`
99	63	`c`
100	64	`d`
101	65	`e`
102	66	`f`
103	67	`g`
104	68	`h`
105	69	`i`
106	6A	`j`
107	6B	`k`
108	6C	`l`
109	6D	`m`
110	6E	`n`
111	6F	`o`
112	70	`p`
113	71	`q`
114	72	`r`
115	73	`s`
116	74	`t`
117	75	`u`
118	76	`v`
119	77	`w`
120	78	`x`
121	79	`y`
122	7A	`z`
123	7B	`{`
124	7C	`\|`
125	7D	`}`
126	7E	`~`
127	7F	`⌂` `⌂` Ctrl+? = Delete

High ASCII (US DOS CP437)

dec	hex	chr
128	80	`Ç` `Ç` Capital C+cedilla
129	81	`ü` `ü` Lowercase u+umlaut
130	82	`é` `é` Lowercase e+acute
131	83	`â` `â` Lowercase a+circumflex
132	84	`ä` `ä` Lowercase a+umlaut
133	85	`à` `à` Lowercase a+grave
134	86	`å` `å` Lowercase a+ring
135	87	`ç` `ç` Lowercase c+cedilla
136	88	`ê` `ê` Lowercase e+circumflex
137	89	`ë` `ë` Lowercase e+umlaut
138	8A	`è` `è` Lowercase e+grave
139	8B	`ï` `ï` Lowercase i+umlaut
140	8C	`î` `î` Lowercase i+circumflex
141	8D	`ì` `ì` Lowercase i+grave
142	8E	`Ä` `Ä` Capital A+umlaut
143	8F	`Â` `Â` Capital A+circumflex
144	90	`É` `É` Capital E+acute
145	91	`æ` `æ` Lowercase a+e Ligature
146	92	`Æ` `Æ` Capital A+E Ligature
147	93	`ô` `ô` Lowercase o+circumflex
148	94	`ö` `ö` Lowercase o+umlaut
149	95	`ò` `ò` Lowercase o+grave
150	96	`û` `û` Lowercase u+circumflex
151	97	`ù` `ù` Lowercase u+grave
152	98	`ÿ` `ÿ` Lowercase y+umlaut
153	99	`Ö` `Ö` Capital O+umlaut
154	9A	`Ü` `Ü` Capital U+umlaut
155	9B	`¢` `¢` Cent
156	9C	`£` `£` Pound Sterling
157	9D	`¥` `¥` Yen
158	9E	`₧` `₧` Peseta
159	9F	`ƒ` `&fnof;` Function-Of

dec	hex	chr
160	A0	`á` `á` Lowercase a+acute
161	A1	`í` `í` Lowercase i+acute
162	A2	`ó` `ó` Lowercase o+acute
163	A3	`ú` `ú` Lowercase u+acute
164	A4	`ñ` `ñ` Lowercase n+tilde
165	A5	`Ñ` `Ñ` Capital N+tilde
166	A6	`ª` `ª` Ordinal Feminine
167	A7	`º` `º` Ordinal Masculine
168	A8	`¿` `¿` Inverted Question Mark
169	A9	`⌐` `⌐` Not/Bracket
170	AA	`¬` `¬` Not/Bracket
171	AB	`½` `½` Fraction 1/2
172	AC	`¼` `¼` Fraction 1/4
173	AD	`¡` `¡` Inverted Exclamation Mark
174	AE	`«` `«` Left Angle Quotes
175	AF	`»` `»` Right Angle Quotes
176	B0	`░` `&blk14;` `░` Shaded Block 1/4
177	B1	`▒` `&blk12;` `▒` Shaded Block 1/2
178	B2	`▓` `&blk34;` `▓` Shaded Block 3/4
179	B3	`│` `&#x2502`
180	B4	`┤` `&#x2524`
181	B5	`╡` `&#x2561`
182	B6	`╢` `&#x2562`
183	B7	`╖` `&#x2556`
184	B8	`╕` `&#x2555`
185	B9	`╣` `&#x2563`
186	BA	`║` `&#x2551`
187	BB	`╗` `&#x2557`
188	BC	`╝` `&#x255D`
189	BD	`╜` `&#x255C`
190	BE	`╛` `&#x255B`
191	BF	`┐` `&#x2510`

dec	hex	chr
192	C0	`└` `└`
193	C1	`┴` `┴`
194	C2	`┬` `┬`
195	C3	`├` `├`
196	C4	`─` `─`
197	C5	`┼` `┼`
198	C6	`╞` `╞`
199	C7	`╟` `╟`
200	C8	`╚` `╚`
201	C9	`╔` `╔`
202	CA	`╩` `╩`
203	CB	`╦` `╦`
204	CC	`╠` `╠`
205	CD	`═` `═`
206	CE	`╬` `╬`
207	CF	`╧` `╧`
208	D0	`╨` `╨`
209	D1	`╤` `╤`
210	D2	`╥` `╥`
211	D3	`╙` `╙`
212	D4	`╘` `╘`
213	D5	`╒` `╒`
214	D6	`╓` `╓`
215	D7	`╫` `╫`
216	D8	`╪` `╪`
217	D9	`┘` `┘`
218	DA	`┌` `┌`
219	DB	`█` `&block;` `█` Solid Block
220	DC	`▄` `▄`
221	DD	`▌` `▌`
222	DE	`▐` `▐`
223	DF	`▀` `▀`

dec	hex	chr
224	E0	`α` `α` Lowercase alpha
225	E1	`β` `β` Lowercase beta
226	E2	`Γ` `Γ` Capital Gamma
227	E3	`π` `π` Lowercase pi
228	E4	`Σ` `Σ` Capital Sigma
229	E5	`σ` `σ` Lowercase sigma
230	E6	`µ` `µ` Micro
231	E7	`τ` `τ` Lowercase tau
232	E8	`Φ` `Φ` Capital Phi
233	E9	`θ` `θ` Lowercase theta
234	EA	`Ω` `Ω` Capital Omega
235	EB	`δ` `δ` Lowercase delta
236	EC	`∞` `∞` Infinity
237	ED	`∅` `∅` Empty Set
238	EE	`∈` `∈` Is-In
239	EF	`∩` `∩` Intersection Cap
240	F0	`≡` `&equiv;` Equivalent
241	F1	`±` `±` Plus Or Minus
242	F2	`≥` `≥` Greater-Than-Or-Equal-To
243	F3	`≤` `≤` Less-Than-Or-Equal-To
244	F4	`⌠` `⌠` Integral Top
245	F5	`⌡` `⌡` Integral Bottom
246	F6	`÷` `÷` Divide
247	F7	`≈` `≈` Asymptotic
248	F8	`°` `°` Degree
249	F9	`·` `·` `∙` Middle Dot
250	FA	`⋅` `⋅` `⋅` Small Dot
251	FB	`√` `√` Square Root
252	FC	`ⁿ` `ⁿ` Superscript n
253	FD	`²` `²` Superscript 2
254	FE	`■` `&x25A0;` Square
255	FF	?

Windows-1252 (mostly Unicode)

dec	hex	chr
128	80	`€` `€` Euro
129	81	`?` undefined
130	82	`‚` `&sbquo;` Single Bottom Quote
131	83	`ƒ` `&fnof;` Function-Of
132	84	`„` `&bdquo;` Bottom Double Quotes
133	85	`…` `…` Horizontal Ellipsis
134	86	`†` `&dagger;` Dagger
135	87	`‡` `&Dagger;` Double Dagger
136	88	`ˆ` `&circ;` Circumflex
137	89	`‰` `&permil;` Per-Mille
138	8A	`Š` `&Scaron;` Capital S+caron
139	8B	`‹` `&lsaquo;` Left Single Angle Quote
140	8C	`Œ` `&OElig;` Capital O+E Ligature
141	8D	`?` undefined
142	8E	`Ž` `Ž` Capital Z+caron
143	8F	`?` undefined
144	90	`?` undefined
145	91	`‘` `‘` `‘` Left Single Quote
146	92	`’` `’` `’` Right Single Quote
147	93	`“` `“` `“` Left Double Quotes
148	94	`”` `”` `”` Right Double Quotes
149	95	`•` `•` Bullet
150	96	`–` `–` En Dash
151	97	`—` `—` Em Dash
152	98	`˜` `&tilde;` Tilde
153	99	`™` `™` Trademark
154	9A	`š` `&scaron;` Lowercase s+caron
155	9B	`›` `&rsaquo;` Right Single Angle Quote
156	9C	`œ` `&oelig;` Lowercase o+e Ligature
157	9D	`?` undefined
158	9E	`ž` `ž` Lowercase z+caron
159	9F	`Ÿ` `&Yuml;` Capital Y+umlaut

dec	hex	chr
160	A0	` ` No-Break Space
161	A1	`¡` `¡` Inverted Exclamation Mark
162	A2	`¢` `¢` Cent
163	A3	`£` `£` Pound Sterling
164	A4	`¤` `¤` Currency
165	A5	`¥` `¥` Yen
166	A6	`¦` `¦` Broken Vertical Bar
167	A7	`§` `§` Section
168	A8	`¨` `¨` Umlaut
169	A9	`©` `©` Copyright
170	AA	`ª` `ª` Ordinal Feminine
171	AB	`«` `«` Left Angle Quotes
172	AC	`¬` `¬` Not
173	AD	`` Soft Hyphen
174	AE	`®` `®` Registered Trademark
175	AF	`¯` `¯` Macron/Overline
176	B0	`°` `°` Degree
177	B1	`±` `±` Plus Or Minus
178	B2	`²` `²` Superscript 2
179	B3	`³` `³` Superscript 3
180	B4	`´` `´` Acute
181	B5	`µ` `µ` Micro
182	B6	`¶` `¶` Paragraph
183	B7	`·` `·` Middle Dot
184	B8	`¸` `¸` Cedilla
185	B9	`¹` `¹` Superscript 1
186	BA	`º` `º` Ordinal Masculine
187	BB	`»` `»` Right Angle Quotes
188	BC	`¼` `¼` Fraction 1/4
189	BD	`½` `½` Fraction 1/2
190	BE	`¾` `¾` Fraction 3/4
191	BF	`¿` `¿` Inverted Question Mark

dec	hex	chr
192	C0	`À` `À` Capital a+grave
193	C1	`Á` `Á` Capital A+acute
194	C2	`Â` `Â` Capital A+circumflex
195	C3	`Ã` `Ã` Capital A+tilde
196	C4	`Ä` `Ä` Capital A+umlaut
197	C5	`Å` `Å` Capital A+ring
198	C6	`Æ` `Æ` Capital A+E Ligature
199	C7	`Ç` `Ç` Capital C+cedilla
200	C8	`È` `È` Capital E+grave
201	C9	`É` `É` Capital E+acute
202	CA	`Ê` `Ê` Capital E+circumflex
203	CB	`Ë` `Ë` Capital E+umlaut
204	CC	`Ì` `Ì` Capital I+grave
205	CD	`Í` `Í` Capital I+acute
206	CE	`Î` `Î` Capital I+circumflex
207	CF	`Ï` `Ï` Capital I+umlaut
208	D0	`Ð` `Ð` Capital Eth
209	D1	`Ñ` `Ñ` Capital N+tilde
210	D2	`Ò` `Ò` Capital O+grave
211	D3	`Ó` `Ó` Capital O+acute
212	D4	`Ô` `Ô` Capital O+circumflex
213	D5	`Õ` `Õ` Capital O+tilde
214	D6	`Ö` `Ö` Capital O+umlaut
215	D7	`×` `×` Times
216	D8	`Ø` `Ø` Capital O+slash
217	D9	`Ù` `Ù` Capital U+grave
218	DA	`Ú` `Ú` Capital U+acute
219	DB	`Û` `Û` Capital U+circumflex
220	DC	`Ü` `Ü` Capital U+umlaut
221	DD	`Ý` `Ý` Capital Y+acute
222	DE	`Þ` `Þ` Capital Thorn
223	DF	`ß` `ß` Lowercase s+z Ligature

dec	hex	chr
224	E0	`à` `à` Lowercase a+grave
225	E1	`á` `á` Lowercase a+acute
226	E2	`â` `â` Lowercase a+circumflex
227	E3	`ã` `ã` Lowercase a+tilde
228	E4	`ä` `ä` Lowercase a+umlaut
229	E5	`å` `å` Lowercase a+ring
230	E6	`æ` `æ` Lowercase a+e Ligature
231	E7	`ç` `ç` Lowercase c+cedilla
232	E8	`è` `è` Lowercase e+grave
233	E9	`é` `é` Lowercase e+acute
234	EA	`ê` `ê` Lowercase e+circumflex
235	EB	`ë` `ë` Lowercase e+umlaut
236	EC	`ì` `ì` Lowercase i+grave
237	ED	`í` `í` Lowercase i+acute
238	EE	`î` `î` Lowercase i+circumflex
239	EF	`ï` `ï` Lowercase i+umlaut
240	F0	`ð` `ð` Lowercase eth
241	F1	`ñ` `ñ` Lowercase n+tilde
242	F2	`ò` `ò` Lowercase o+grave
243	F3	`ó` `ó` Lowercase o+acute
244	F4	`ô` `ô` Lowercase o+circumflex
245	F5	`õ` `õ` Lowercase o+tilde
246	F6	`ö` `ö` Lowercase o+umlaut
247	F7	`÷` `÷` Divide
248	F8	`ø` `ø` Lowercase o+slash
249	F9	`ù` `ù` Lowercase u+grave
250	FA	`ú` `ú` Lowercase u+acute
251	FB	`û` `û` Lowercase u+circumflex
252	FC	`ü` `ü` Lowercase u+umlaut
253	FD	`ý` `ý` Lowercase y+acute
254	FE	`þ` `þ` Lowercase thorn
255	FF	`ÿ` `ÿ` Lowercase y+umlaut

Α

Β

Γ

Δ

Ε

Ζ

Η

Θ

Ι

Κ

Λ

Μ

Ν

Ξ

Ο

Π

Ρ

Σ

Τ

Υ

Φ

Χ

Ψ

Ω

α

β

γ

δ

ε

ζ

η

θ

ι

κ

λ

μ

ν

ξ

ο

π

ρ

σ

τ

υ

φ

χ

ψ

ω

↵

⇐

⇒

⇑

⇓

⇔

✓

✔

✗

☐

☑

☒

⎋

⌘

⌥

⎇

⇧

⏎

⏏

⌨

⎊

Operator Precedence (Order of Operations)

C++

Category Operators Ass.

highest

`()`	precedence or function call
`[]`	array subscript
`::`	scope resolution
`.`	member selector
`->`	dereferenced member selector

LTR →

unary

`!`	logical NOT
`~`	bitwise NOT
`+`	unary positive
`-`	unary negative
`++`	increment
`--`	decrement
`&`	reference (address of)
`*`	dereference (pointed to)
`(type)`	typecasting
`sizeof`	returns size of operand in bytes
`new`	object construction
`delete`	object destruction

← RTL

arithmetical

`*`	multiplication
`/`	division
`%`	modulus (remainder)

LTR →

arithmetical

`+`	addition
`-`	subtraction

LTR →

bit shift

`<<`	shift left
`>>`	shift right

LTR →

relational

`<`	less than
`<=`	less than or equal to
`>`	greater than
`>=`	greater than or equal to

LTR →

relational

`==`	equal to
`!=`	not equal to

LTR →

8 bitwise AND & bitwise AND LTR →

9 bitwise XOR ^ bitwise XOR LTR →

10 bitwise OR | bitwise OR LTR →

11 logical AND && logical AND LTR →

12 logical OR || logical OR LTR →

13 ternary conditional a?b:c means "if a, then b, else c" ← RTL

assignment

`=`	assignment
`*=`	assign product
`/=`	assign quotient
`%=`	assign remainder (modulus)
`+=`	assign sum
`-=`	assign difference
`&=`	assign bitwise AND
`^=`	assign bitwise XOR
`\|=`	assign bitwise OR
`<<=`	assign left shift
`>>=`	assign right shift

← RTL

15 comma , evaluation separator comma LTR →

C#

	Category	Operators	Ass.
1	Primary	`x.y` `x?.y` null-conditional `x::y` `f(x)` `a[x]` `a?[x]` `x++` `x--` `new` `typeof` `checked` `unchecked` `default` `sizeof` `nameof` `->` `delegate{}`	LTR →
2	Unary	`+` `-` `!` `~` `++x` `--x` `(T)x` `await` `&` `*`	← RTL
3	Multiplicative	`*` `/` `%`	LTR →
4	Additive	`+` `-`	LTR →
5	Shift	`<<` `>>`	LTR →
6	Relational	`<` `>` `<=` `>=` `is` `as`	LTR →
7	Equality	`==` `!=`	LTR →
8	AND	`&` bitwise or non-short-circuiting logical AND	LTR →
9	XOR	`^` bitwise or logical XOR	LTR →
10	OR	`\|` bitwise or non-short-circuiting logical OR	LTR →
11	AND	`&&` logical AND	LTR →
12	OR	`\|\|` logical OR	LTR →
13	Null-coalesce	`??` null-coalesce	LTR →
14	Conditional	`x?y:z`	← RTL
15	Assignment	`=` `*=` `/=` `%=` `+=` `-=` `<<=` `>>=` `&=` `^=` `\|=` `=>` (lambda)	← RTL

Python 3

Operators Ass.

`()`	precedence or tuple display
`[]`	list display
`{}`	dictionary or set display

LTR →

`[]`	subscription or slicing
`()`	function call
`.`	attribute reference

LTR →

3 await LTR →

4 ** exponentiation ← RTL

`+`	unary positive
`-`	unary negative
`~`	bitwise NOT

LTR →

`*`	multiplication
`@`	matrix multiplication
`/`	float division
`//`	integer division
`%`	remainder or string formatting

LTR →

`+`	addition
`-`	subtraction

LTR →

`<<`	shift left
`>>`	shift right

LTR →

9 & bitwise AND LTR →

10 ^ bitwise XOR LTR →

11 | bitwise OR LTR →

in

not in

is

is not

<

<=

>

>=

!=

==

LTR →

13 not boolean NOT LTR →

14 and boolean AND LTR →

15 or boolean OR LTR →

16 if-else LTR →

17 lambda LTR →

18 yield LTR →

Non-Operators

`=`	assignment
`**=`
`*=`
`@=`
`/=`
`//=`
`%=`
`+=`
`-=`
`&=`
`^=`
`\|=`
`<<=`
`>>=`

Lua

Category Operators Ass.

highest

`()`	precedence or function call
`[]`	table indexer
`{}`	table constructor
`.`	table string indexer
`:`	table this indexer

LTR →

2 exponentiation ^ exponentiation ← RTL

unary

`not`	logical not
`#`	count
`-`	negation

LTR →

multiplicative

`*`	multiplication
`/`	division
`%`	modulo

LTR →

additive

`+`	addition
`-`	subtraction

LTR →

6 concatenation .. string concatenation ← RTL

relational

`==`	equal
`~=`	not equal
`<`	less than
`<=`	less than or equal to
`>`	greater than
`>=`	greater than or equal to

LTR →

8 logical and and LTR →

9 logical or or LTR →

Non-Operators

Assignment = assignment

PHP

Category Operators Ass.

1 allocation clone
new no

2 array []
{} LTR →

3 exponentiation ** ← RTL

4 unary ++
--
~
-
(int)
(float)
(string)
(array)
(object)
(bool)
@ ← RTL

5 types instanceof no

6 logical ! ← RTL

7 multiplicative *
/
% LTR →

8 additive +
-
. LTR →

9 bitwise <<
>> LTR →

10 comparison <
<=
>
>= no

comparison

`==`	equal
`!=`	not equal
`===`	identical
`!==`	not identical
`<>`	not equal
`<=>`	Spaceship

12 bitwise and references & LTR →

13 bitwise ^ LTR →

14 bitwise | LTR →

15 logical && LTR →

16 logical || LTR →

17 coalesce ?? ← RTL

18 ternary ?: LTR →

19 assignment =
+=
-=
*=
/=
.=
%=
&=
|=
^=
<<=
>>=
=> (key-value) ← RTL

20 yield yield ← RTL

21 print print ← RTL

22 logical and LTR →

23 logical xor LTR →

24 logical or LTR →

25 misc. , LTR →

JS

Category Operators Ass.

highest

`.`	member access
`()`	precedence or function call
`[]`	array indexing
`new`	object creation

LTR →

unary

`++`	increment
`--`	decrement
`!`	logical NOT
`~`	bitwise NOT
`+`	unary positive
`-`	unary negative
`delete`	object destruction
`typeof`	reflection
`void`

← RTL

multiplication

`*`	multiplication
`/`	division
`%`	modulus (remainder)

LTR →

addition

`+`	addition or concatenation
`-`	subtraction

LTR →

bit shift

`<<`	shift left
`>>`	shift right
`>>>`	shift right unsigned

LTR →

relational

`<`	less than
`<=`	less than or equal to
`>`	greater than
`>=`	greater than or equal to
`in`
`instanceof`

LTR →

equality

`==`	equal to
`!=`	not equal to
`===`	strict equal to
`!==`	strict not equal to

LTR →

8 bitwise AND & bitwise AND LTR →

9 bitwise XOR ^ bitwise XOR LTR →

10 bitwise OR | bitwise OR LTR →

11 logical AND && logical AND LTR →

12 logical OR || logical OR LTR →

13 conditional a?b:c means "if a, then b, else c" ← RTL

14 yield yield ← RTL

15 assignment =
*=
/=
%=
+=
-=
<<=
>>=
>>>=
&=
^=
|= ← RTL

16 comma , evaluation separator comma LTR →

MySQL 5

Operators Ass.

1 INTERVAL

2 BINARY
COLLATE

3 ! logical NOT

`-`	unary negative
`~`	unary bit inversion

5 ^ bitwise XOR

`*`	multiplication
`/`	division
`%`	modulo (remainder)
`DIV`	integer division
`MOD`	modulo (remainder)

`+`	addition
`-`	subtraction

`<<`	left shift
`>>`	right shift

9 & bitwise AND

10 | bitwise OR

`=`	equal
`<=>`	null-safe equal
`>=`	greater than or equal
`>`	greater than
`<=`	less than or equal
`<`	less than
`<>`	not equal
`!=`	not equal
`IS`	boolean test
`LIKE`	pattern matching
`REGEXP`	RegEx matching
`IN`	set matching

`BETWEEN`
`CASE`

13 NOT logical NOT

`&&`	logical AND
`AND`	logical AND

15 XOR logical XOR

`\|\|`	logical OR
`OR`	logical OR

17 := assignment

T-SQL

Operators Ass.

1 ~ Bitwise NOT

`*`	Multiply
`/`	Division
`%`	Modulo

`+`	Positive
`-`	Negative
`+`	Add
`+`	Concatenate
`-`	Subtract
`&`	Bitwise AND

=
>
<
>=
<=
<>
!=
!>
!< Comparison operators

`^`	Bitwise XOR
`\|`	Bitwise OR

6 NOT

7 AND

8 ALL
ANY
BETWEEN
IN
LIKE
OR
SOME

Non-Operators

= Assignment

Regular Expressions

Operators Ass.

1 \s escape LTR →

2 [] LTR →

3 () group LTR →

`?`	zero or one
`+`	one or many
`*`	zero or many
`{}`	repetition

LTR →

`.`	sequences of characters
`a`
`b`
`c`

LTR →

`^`	anchor
`$`

LTR →

7 | alternator LTR →

Escape Sequences used in string literals

hex	ASCII/description	C++ escape code	C# escape code	Python 3 escape code	Lua escape code	PHP escape code	JS escape code	JSON escape code	MySQL 5 escape code
00	null-zero terminator	`\0`	`\0`	`\0`	`\0`	`\0`	`\0`¹		`\0`
07	audible bell / alert	`\a`	`\a`	`\a`	`\a`
08	backspace	`\b`	`\b`	`\b`	`\b`		`\b`	`\b`	`\b`
09	horizontal tab	`\t`	`\t`	`\t`	`\t`	`\t`	`\t`	`\t`	`\t`
0A	new line	`\n`	`\n`	`\n`	`\n`	`\n`	`\n`	`\n`	`\n`
0B	vertical tab	`\v`	`\v`	`\v`	`\v`	`\v`	`\v`¹
0C	form feed	`\f`	`\f`	`\f`	`\f`	`\f`	`\f`	`\f`
0D	carriage return	`\r`	`\r`	`\r`	`\r`	`\r`	`\r`	`\r`	`\r`
1A	end of file (Ctrl+Z)								`\Z`
22	double quote (for use in double-quote literals)	`\"`	`\"`	`\"`	`\"`	`\"`	`\"`	`\"`	`\"`
24	dollar sign					`\$`
27	single quote (for use in single-quote literals)	`\'`	`\'`	`\'`	`\'`		`\'`		`\'` or `''`
2F	forward slash							`\/`
5B	left square bracket				`\[`
5C	backslash character	`\\`	`\\`	`\\`	`\\`	`\\`	`\\`	`\\`	`\\`
5D	right square bracket				`\]`
*	octal number (such as `"\40"` for ASCII space)	`\#`		`\#`		`\#`
*	decimal number (such as `"\233"` for Unicode é)				`\#`
*	hexadecimal number (such as `"\xE9"` for Unicode é)	`\x#`	`\x#`	`\x##`		`\x#`	`\x##`
*	Unicode (hexadecimal, such as `"\u2192"` for right arrow)		`\u####`	`\u####`		`\u{#}`	`\u####`	`\u####`
*	Unicode surrogate		`\u########`	`\u########`
	backslash at end of line continues string (without newline)	`\EOL`		`\EOL`			`\EOL`
0A	backslash at end of line causes newline				`\EOL`

¹Only recognized in modern browsers.

Data Types

description	range	ASM keywords	C++ keywords	C# keywords	PHP keywords	MySQL 5 keywords	T-SQL keywords
integer, 8 bits, unsigned	0 thru +255	`BYTE`	`unsigned char`	`byte`		`TINYINT UNSIGNED`	`TINYINT`
integer, 8 bits, including a sign bit	-128 thru +127	`SBYTE`^[7]	`char`^{[1, 2, 3, 5]}, `signed char`	`sbyte`		`TINYINT`, `BOOL`, `BOOLEAN`, `INT1`
integer, 16 bits, unsigned	0 thru +65,535	`WORD`^[8]	`unsigned short`, `unsigned short int`	`char`^[3], `ushort`		`SMALLINT UNSIGNED`
integer, 16 bits, including a sign bit	-32,768 thru +32,767	`SWORD`^[7]	`short`^[1], `short int`, `signed short`, `signed short int`	`short`		`SMALLINT`, `INT2`	`SMALLINT`
integer, 24 bits, unsigned	0 thru +16,777,215					`MEDIUMINT UNSIGNED`
integer, 24 bits, including a sign bit	-8,388,608 thru +8,388,607					`MEDIUMINT`, `INT3`
integer, 32 bits, unsigned	0 thru +4,294,967,295	`DWORD`	`unsigned long`, `unsigned long int`	`uint`		`INT UNSIGNED`, `INTEGER UNSIGNED`
integer, 32 bits, including a sign bit	-2,147,483,648 thru +2,147,483,647	`SDWORD`^[7]	`int`^{[1, 4, 5]}, `long`^{[1, 6]}, `long int`, `signed long`, `signed long int`	`int`	`int`	`INT`, `INTEGER`, `INT4`	`INT`
integer, 64 bits, unsigned	0 thru +18,446,744,073,709,551,615	`QWORD`	`unsigned long long`, `unsigned long long int`	`ulong`		`BIGINT UNSIGNED`
integer, 64 bits, including a sign bit	-9,223,372,036,854,775,808 thru +9,223,372,036,854,775,807		`long long`, `long long int`, `signed long long`, `signed long long int`	`long`^[6]		`BIGINT`, `INT8`	`BIGINT`
Boolean true/false	false versus true		`bool`^[9]	`bool`	`bool`	`BOOL`	`BIT`
floating-point, 16 bits	±65,504
floating-point, 32 bits	3.4×10^±38	`REAL4`	`float`			`FLOAT`, `FLOAT4`
floating-point, 64 bits	1.7×10^±308	`REAL8`	`double`		`float`	`DOUBLE`, `FLOAT8`
floating-point, 80 bits	3.4×10^-4932 thru 1.1×10⁺⁴⁹³²	`REAL10`	`long double`^[10]
fixed-point...						`DECIMAL`, `DEC`, `NUMERIC`, `FIXED`

notes
1	In C++, when a `char`, `int`, `short`, or `long` is declared without specifying `signed` or `unsigned`, usually but not always the compiler will default to `signed`. Most compilers allow you to control this behavior somewhat, though I have always witnessed `signed` to be the anticipated default.
2	In C++, the language specification says a `char` is always 1 byte, although this may not necessarily be 8 bits, depending on the platform. However, on DOS, Windows, (PC) Linux, and Macintosh platforms, I have always witnessed a `char` to be 8 bits.
3	In C#, a `char` is 16 bits, unsigned, for the purpose of representing Unicode, whereas in C++, a `char` is 8 bits, signed (see above notes), for the purpose of representing ASCII.
4	In C++, a default `int` on old DOS compilers was 16 bits, the same as a `short`, whereas a default `int` on Windows and (PC) Linux compilers is 32 bits, the same as a `long`. And on a few newer platforms, a default `int` is 64 bits. Beware that platforms other than you're used to may consider a default `int` to be a size other than you're used to.
5	In C++, because of the above caveats, I recommend that you specify `signed`, `unsigned`, `short`, and `long` as much as practical. I recommend the use of the unspecific `int` when it's safe for you to not care, and when saving a few bytes via smaller data type offers no discernible advantage versus speed via the default `int`. When the `char` datatype is used to represent text, I recommend no `signed` or `unsigned` specification in order to match the Standard Library.
6	In C#, a `long` is 64 bits, whereas in C++, a `long` is 32 bits.
7	In assembly, the distinction between signed and unsigned data types is determined by the choice of instructions executed upon the data.
8	In assembly, a `WORD` may not necessarily be 16 bits, depending on the platform. However, on DOS and Windows, I have always witnessed a `WORD` to be 16 bits. Mnemonics derived from `WORD`, such as `DWORD` and `QWORD`, are dependent upon the size of `WORD`.
9	In C++, logical operations always result in an integer where zero means false and non-zero means true. So a `bool` is blatantly implemented as an integer, and may be interchangeable with an `int`, depending on the compiler. Older implementations of C++ (pre-1995) did not have a `bool` datatype at all. The size of a `bool` depends on the compiler; some use 4 bytes rather than just 1, etc. In Java and C#, a `bool` is always considered distinct from an integer and not interchangeable.
10	In C++, the actual precision of floating types depends on the compiler. In particular, Microsoft Visual C++ treats a `long double` the same as a 64-bit `double`.

True & False (What is truth, anyway?)

BASH

Zero is true; everything else is false.

C / C++

Zero is false; everything else is true.
NULL is just a common alias for zero.
Datatype bool is a sub-type of int, so false is really a zero.

C#

bool is a distinct datatype; other types cannot be coerced to bool.
- However, internally, false is zero, and true is one.
  (Yet to speak of such things is blasphemy.)

Python 3

The following are false:
- zero
- False
- None
- an empty sequence or mapping, such as '', (), [], {}
- objects that override __bool__ to return False
- objects that override __len__ to return zero
Everything else is true.
Datatype bool is a subclass of int, so False is really a zero.

Lua

false and nil are false; everything else is true.

PHP

The following are false:
- zero
- false
- NULL
- '' (empty string)
- '0'
- array() (empty array)
Everything else is true.
But sometimes comparisons are complicated.

JS

The following are false:
- zero
- false
- '' (empty string)
- null
- undefined
- NAN (not-a-number)
Everything else is true.
But sometimes comparisons are complicated.

MySQL

Zero and NULL are false; everything else is true.
(x = NULL) is always false because NULL is unknown; (x IS NULL) must be used instead.
But all types are coerced to a number before testing, so strings are false if they represent zero.
FALSE is really an alias for zero.

T-SQL

Booleans only exist ephemerally within expressions; there is no boolean type.
(x = NULL) is always false because NULL is unknown; (x IS NULL) must be used instead.
'TRUE' and 'FALSE' (strings) may be auto-converted to datatype BIT.

HTTP status codes


100 Continue
101 Switching Protocols
102 Processing
200 OK
201 Created	Something was created. There should be a `Location` header indicating the thing just created.
202 Accepted	Request accepted, but processing not completed yet.
203 Non-Authoritative Information	A proxy has modified the response.
204 No Content	Request accepted; no response body necessary.
205 Reset Content	Request accepted; agent may reset the input form.
206 Partial Content
207 Multi-Status
208 Already Reported
226 IM Used

300 Multiple Choices	There might be a `Location` header.
301 Moved Permanently	There should be a `Location` header. To `GET` even if it was originally a `POST`.
302 Found	There should be a `Location` header. To `GET` even if it was originally a `POST`. This is supposed to mean a temporary redirect, but some agents treat this like a 303.
303 See Other	There should be a `Location` header. To `GET` in response to a `POST`.
304 Not Modified	In response to an `If-Modified-Since` header. Typically used with images, etc.
305 Use Proxy	Deprecated.
306 Switch Proxy	No longer used.
307 Temporary Redirect	There should be a `Location` header. To hit with the same method (`GET` or `POST`) as the original request.
308 Permanent Redirect	There should be a `Location` header. To hit with the same method (`GET` or `POST`) as the original request.

400 Bad Request
401 Unauthorized	There should be a `WWW-Authenticate` header. In response to an incorrect or missing `Authorization` header, meaning user is not authenticated. This is a prompt for the agent to authenticate by sending the `Authorization` header.
402 Payment Required	Sometimes used when an agent has made too many requests.
403 Forbidden	Meaning user is perhaps authenticated but not authorized (as opposed to a 401).
404 Not Found
405 Method Not Allowed	Regarding `GET`, `POST`, etc.
406 Not Acceptable	In response to an `Accept` header regarding MIME-types, etc.
407 Proxy Authentication Required
408 Request Timeout	In response to an open connection left idle (not due to a request taking too long to fulfill on server side).
409 Conflict
410 Gone	The resource is no longer available on purpose (as opposed to a 404).
411 Length Required
412 Precondition Failed	Regarding "preconditions" of the request.
413 Request Entity Too Large
414 Request-URI Too Long
415 Unsupported Media Type
416 Requested Range Not Satisfiable	The agent requested a byte range of a file that is not available.
417 Expectation Failed	In response to an `Expect` header.
418 I'm a teapot	In response to a request to brew coffee.
419 Authentication Timeout	Non-standard.
420 Method Failure	Non-standard & deprecated.
420 Enhance Your Calm	Intended as a rate-limiting scheme.
421 Misdirected Request	A request was sent over an open HTTP/2 session that should have been sent to a different host.
422 Unprocessable Entity
423 Locked
424 Failed Dependency
425 Too Early	The agent submitted a token considered too old by the server.
426 Upgrade Required	The agent should use more encryption. Or the agent should use a newer version of HTTP.
428 Precondition Required
429 Too Many Requests	Intended as a rate-limiting scheme.
431 Request Header Fields Too Large
440 Login Timeout	Microsoft extension.
444 No Response	Nginx.
449 Retry With	Microsoft extension.
451 Unavailable For Legal Reasons
451 Redirect	Microsoft Exchange ActiveSync.
494 Request Header Too Large	Nginx used this before 431 had been introduced.
495 Cert Error	Nginx.
496 No Cert	Nginx.
497 HTTP to HTTPS	Nginx.
498 Token expired/invalid	Esri ArcGIS Server.
499 Client Closed Request	Nginx.
499 Token required	Esri ArcGIS Server.

500 Internal Server Error
501 Not Implemented
502 Bad Gateway
503 Service Unavailable	Temporary maintenance.
504 Gateway Timeout
505 HTTP Version Not Supported
506 Variant Also Negotiates
507 Insufficient Storage
508 Loop Detected
509 Bandwidth Limit Exceeded
510 Not Extended
511 Network Authentication Required
520 Web server is returning an unknown error	Cloudflare reverse-proxy misc. HTTP problem.
521 Web server is down	Cloudflare reverse-proxy connection refused.
522 Connection timed out	Cloudflare reverse-proxy timeout.
523 Origin is unreachable	Cloudflare reverse-proxy network or DNS problem.
524 A timeout occurred	Cloudflare reverse-proxy timeout.
525 SSL handshake failed	Cloudflare reverse-proxy detected SSL misconfiguration.
526 Invalid SSL certificate	Cloudflare reverse-proxy found bad SSL cert.
598 Network read timeout error	Microsoft.
599 Network connect timeout error	Microsoft.

Radix Translation

between numeral systems

dec (10)	bin (2)	hex (16)	oct (8)
0	0	0	0
1	1	1	1
2	10	2	2
3	11	3	3
4	100	4	4
5	101	5	5
6	110	6	6
7	111	7	7
8	1000	8	10
9	1001	9	11
10	1010	A	12
11	1011	B	13
12	1100	C	14
13	1101	D	15
14	1110	E	16
15	1111	F	17
16	10000	10	20

Byte Units

K	kilobyte	= 1024 = 2¹⁰ bytes, or over a thousand bytes	> 10³
M	megabyte	= 1024² = 1,048,576 bytes, or over a million bytes	> 10⁶
G	gigabyte	= 1024³ = 1,073,741,824 bytes, or over a billion (milliard) bytes	> 10⁹
T	terabyte	= 1024⁴ = 1,099,511,627,776 bytes, or over a trillion bytes	> 10¹²
P	petabyte	= 1024⁵ = 1,125,899,906,842,624 bytes, or over a quadrillion (billiard) bytes	> 10¹⁵
E	exabyte	= 1024⁶ = 1,152,921,504,606,846,976 bytes, or over a quintillion bytes	> 10¹⁸
Z	zettabyte	= 1024⁷ = 1,180,591,620,717,411,303,424 bytes, or over a sextillion (trilliard) bytes	> 10²¹
Y	yottabyte	= 1024⁸ = 1,208,925,819,614,629,174,706,176 bytes, or over a septillion bytes	> 10²⁴

More fun byte units:

An octet is another name for a regular old byte with 8 bits.
A word is 2 bytes, or 16 bits, or it may be larger depending on the platform.
There is also a double word (DWORD) and quad word (QWORD), which represent various sizes of integer.
A paragraph is 16 bytes, depending on the platform, though this is pretty archaic today.
A nibble is half of a byte, or 4 bits. One hexadecimal digit represents one nibble.

CSS Jargon

p.ExampleClassselector { vertical-alignproperty: middlevaluedeclaration; outlineproperty: 1px dashed Redvaluedeclaration; }declaration-blockrule/statement

@charset "utf-8";at-rule/statement

@media (min-width: 801px)at-rule { body { background-color: Blue; }nested-rule }nested-statement

Confusing Version Numbers

MacOS X

commonly	internally	released
Cheetah	10.0	2001
Puma	10.1	2001
Jaguar	10.2	2002
Panther	10.3	2003
Tiger	10.4	2005
Leopard	10.5	2007
Snow Leopard	10.6	2009
Lion	10.7	2011
Mountain Lion	10.8	2012
Mavericks	10.9	2013
Yosemite	10.10	2014
El Capitan	10.11	2015
Sierra	10.12	2016
High Sierra	10.13	2017
Mojave	10.14	2018
Catalina	10.15	2019

Windows

commonly	internally	released
1.x	1.x	1985
2.x	2.x	1987
3.x	3.x	1990
NT 3.x	NT 3.x	1993
95	4.0	1995
NT 4	NT 4.0	1996
97 Just kidding!	4.01	1997
98	4.10	1998
98 SE	4.10	1999
2000	NT 5.0	2000
ME	4.90	2000
XP	NT 5.1	2001
Server 2003	NT 5.2	2003
XP x64	NT 5.2	2005
Server 2003 R2	NT 5.2	2006
Vista	NT 6.0	2007
Server 2008	NT 6.0	2008
Server 2008 R2	NT 6.1	2009
7	NT 6.1	2009
Server 2012	NT 6.2	2012
8	NT 6.2	2012
8.1	NT 6.3	2013
Server 2012 R2	NT 6.3	2013
10	NT 10.0	2015
Server 2016	NT 10.0	2016
Server 2019	NT 10.0	2018

DirectX

commonly	internally	released
1.0	4.02.0095	1995
2.0a	4.03.00.1096	1996
3.0	4.04.00.0068	1996
3.0a	4.04.00.0070	1996
3.0b	4.04.00.0070	1996
5.0	4.05.00.0155	1997
5.2	4.05.01.1600	1998
6.0	4.06.00.0318	1998
6.1	4.06.02.0436	1999
6.1a	4.06.03.0518	1999
7.0	4.07.00.0700	1999
7.0a	4.07.00.0716	2000
7.1	4.07.01.3000	2000
8.0	4.08.00.0400	2000
8.0a	4.08.00.0400	2001
8.1	4.08.01.0810	2001
8.1a	4.08.01.0901	2002
8.1b	4.08.01.0901	2002
8.2	4.08.02.0134	2002
9.0	4.09.00.0900	2002
9.0a	4.09.00.0901	2003
9.0b	4.09.00.0902	2003
9.0c	4.09.00.0904	2004
10	6.00.6000.16386	2006
10.1	6.00.6001.18000	2008
11	6.01.7600.16385	2009
11.1	6.02.9200.16384	2012
11.2	6.03.9600.16384	2013
12	10.00.10240.16384	2015

Visual Studio

commonly	internally	released	C#	.NET Framework	.NET Core
97	5.0	1997
6.0	6.0	1998
.NET	7.0	2002	1.0	1.0
.NET 2003	7.1	2003	1.1	1.1
2005	8.0	2005	2.0	2.0
2008	9.0	2007	3.0	3.5
2010	10.0	2010	4.0	4.0
2012	11.0	2012	5.0	4.5
2013	12.0	2013	5.0	4.5.1
2015	14.0	2015	6.0	4.6	1.0
2017	15.0	2017	7.x	4.7	2.0
2019	16.0	2019	7.x	4.8	3.0

SQL Server

commonly	internally	released	compatibility level
7.0	7.0	1998	compatibility level
2000	8.0	2000	80
2005	9.0	2005	90
2008	10.0	2008	100
2008 R2	10.50	2010	100
2012	11.0	2012	110
2014	12.0	2014	120
2016	13.0	2016	130
2017	14.0	2017	140
2019	15.0	2019	150
2022	16.0	2022	160

Programmer Cheat Sheets

ASCII Chart

High ASCII (US DOS CP437)

Windows-1252 (mostly Unicode)

Operator Precedence (Order of Operations)

C++

C#

Python 3

Lua

PHP

JS

MySQL 5

T-SQL

Regular Expressions

Escape Sequences used in string literals

C++

C#

Python 3

Lua

PHP

JS

JSON

MySQL 5

Data Types

ASM

C++

C#

PHP

MySQL 5

T-SQL

True & False (What is truth, anyway?)

BASH

C / C++

C#

Python 3

Lua

PHP

JS

MySQL

T-SQL

HTTP status codes

Radix Translation

Byte Units

CSS Jargon

Confusing Version Numbers

MacOS X

Windows

DirectX

Visual Studio

SQL Server

See also my links page.

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