PHP
PHP Standard Functions
Function
Description
isset(el)
Will return false if ๎el ๎has been assigned the constant NULL, ๎el ๎has not
been set to any value yet (undefined) ๎el ๎has been deleted using the
unset function
print str
echo str
Prints ๎str
time()
Returns the current time in seconds
date(format, time)
Converts an optional ๎time ๎in seconds to a date based on ๎format
mt rand(min, max)
Returns a random integer between ๎min ๎and ๎max ๎(inclusive)
header(string)
Sends a raw HTTP header. Examples include:
header("HTTP/1.1 400 Invalid Request");
header("Content-type: text/plain");
header("Content-type: application/json");
die(message)
Ends execution and sends back optional ๎message
include "path"
Includes and evaluates the specified file ๎path๎ such as
"hidden/config.php"
PHP Array Functions
Function
Description
count(arr)
Returns the length of an array ๎arr
print_r(arr)
Prints the ๎arr๎โs contents
array_pop(arr)
Pops (removes) an element off the end of the array ๎arr
array_shift(arr)
Shifts (removes) an element off the beginning of the array ๎arr
array_push(arr, el)
Pushes (adds) one or more elements onto the end of the array ๎arr
array_unshift(arr, el)
Prepends one or more elements to the beginning of the array ๎arr
sort(arr)
Sorts the array ๎arr
array_reverse(arr)
Returns an array with elements of ๎arr ๎in reverse order
in_array(el, arr)
Returns whether a value ๎el ๎exists in an array ๎arr
list(a, b, ...)
Assigns variables as if they were an array
implode(glue, pieces)
Joins array elements (๎pieces๎) with a string (๎glue๎)
array_rand(arr)
Randomly selects a random entry from the array and returns the key
(or keys) of the random entries.
PHP JSON Functions
Function
Description
json_encode(obj)
Returns JSON equivalent for the given object/array/value
json_decode(string
)
Parse the given JSON data string and returns an equivalent associative array
object
CSE 154 Exam Cheat Sheet Spring 2019 - Version 05/03/19
