Programming Language Keywords

This page shows statistics on the popularity of keywords and other reserved words across a number of programming languages. Ten languages have been selected, to get good coverage of contemporary coding practices.

	Keyword (permanently reserved word)
	Contextual (reserved in some contexts)

Keywords shared by 10 languages
Keyword	C	C#	Go	Java	JS	Perl	PHP	Python	Ruby	Rust
else
for
if
return
Keywords shared by 9 languages
Keyword	C	C#	Go	Java	JS	Perl	PHP	Python	Ruby	Rust
break
while
Keywords shared by 8 languages
Keyword	C	C#	Go	Java	JS	Perl	PHP	Python	Ruby	Rust
case
continue
do
Keywords shared by 7 languages
Keyword	C	C#	Go	Java	JS	Perl	PHP	Python	Ruby	Rust
const
default
false								False
true								True
yield
Keywords shared by 6 languages
Keyword	C	C#	Go	Java	JS	Perl	PHP	Python	Ruby	Rust
class
goto
static
switch
try
Keywords shared by 5 languages
Keyword	C	C#	Go	Java	JS	Perl	PHP	Python	Ruby	Rust
and
as
enum
finally
in
interface
or
super
var
Keywords shared by 4 languages
Keyword	C	C#	Go	Java	JS	Perl	PHP	Python	Ruby	Rust
abstract
async
await
catch
float
from
import
int
long
new
null
package
private
protected
public
struct
throw
void
with
Keywords shared by 3 languages
Keyword	C	C#	Go	Java	JS	Perl	PHP	Python	Ruby	Rust
char
double
eval
extends
extern
final
foreach
global
implements
instanceof
let
map
match
next
not
print
self
set
short
this
type
typeof
use
volatile
when
Keywords shared by 2 languages
Keyword	C	C#	Go	Java	JS	Perl	PHP	Python	Ruby	Rust
alias
assert
bool
byte
callable
cmp
def
elsif
exit
fn
format
function
get
is
list
module
namespace
object
open
override
range
readonly
record
redo
ref
require
sealed
select
sizeof
trait
unless
unsafe
until
virtual
where
xor

Keywords unique to a single language

C

auto
inline
register
restrict
signed
typedef
union
unsigned

C#

add
ascending
base
by
checked
decimal
delegate
descending
dynamic
equals
event
explicit
fixed
group
implicit
init
internal
into
join
lock
managed
nameof
nint
notnull
nuint
on
operator
orderby
out
params
partial
remove
sbyte
stackalloc
string
uint
ulong
unchecked
ushort
using
value

Go

chan
defer
fallthrough
func
go

Java

boolean
exports
native
non-sealed
opens
permits
provides
requires
strictfp
synchronized
throws
to
transient
transitive
uses

JS

debugger
delete
export
of
target

Perl

CORE
dump
eq
ge
given
grep
gt
last
le
local
lt
m
my
ne
no
our
printf
q
qq
qr
qw
qx
s
say
sort
state
sub
tr
x
y

PHP

array
clone
declare
die
echo
elseif
empty
enddeclare
endfor
endforeach
endif
endswitch
endwhile
include
include_once
insteadof
isset
parent
require_once
unset

Python

abs
aiter
all
anext
any
apply
ascii
basestring
bin
breakpoint
buffer
bytearray
bytes
chr
classmethod
coerce
compile
complex
copyright
credits
del
delattr
dict
dir
divmod
elif
Ellipsis
enumerate
except
exec
execfile
file
filter
frozenset
getattr
globals
hasattr
hash
help
hex
id
input
intern
isinstance
issubclass
iter
lambda
len
license
locals
max
memoryview
min
None
nonlocal
NotImplemented
oct
ord
pass
pow
property
quit
raise
raw_input
reduce
reload
repr
reversed
round
setattr
slice
sorted
staticmethod
str
sum
tuple
unichr
unicode
vars
xrange
zip

Ruby

begin
defined?
end
ensure
nil
rescue
retry
then
undef

Rust

become
box
crate
dyn
impl
loop
macro
mod
move
mut
priv
pub
unsized

Programming Language Keywords

Keywords shared by 10 languages

Keywords shared by 9 languages

Keywords shared by 8 languages

Keywords shared by 7 languages

Keywords shared by 6 languages

Keywords shared by 5 languages

Keywords shared by 4 languages

Keywords shared by 3 languages

Keywords shared by 2 languages