Functions

String

parse_str()
isset()
define()
http_build_query()
strlen()
str_word_count()
strrev()
strpos()
str_replace()

Sessions

session_start()
session_abort()
session_reset()
session_destroy()
$_SESSION[]

Numbers

is_float()
is_numeric()
pi()
min()
max()
abs()
sqrt()
round()
rand()

Array and Objects

array()
[]
count()
in_array()
sort()
rsort()
asort()
arsort()
ksort()
krsort()

JSON

json_encode()
json_decode()

Encryption

base64_encode()
base64_decode()

Global Variables

$_COOKIE[]
$_POST[]
$_GLOBALS[]
$_SERVER[]
get()
querystring()

File control

file_get_contents()
file_put_contents()

Others

die()
setcookie()
echo()
print()
print_r()
header()
unset()