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PHP Keywords

PHP Keywords

PHP has a set of keywords that are reserved words which cannot be used as function names, class names or method names. Prior to PHP 7, these keywords could not be used as class property names either:

Keyword Description
abstract Declare a class as abstract
and A logical operator
as Used in the foreach loop
break Break out of loops and switch statements
callable A data type which can be executed as a function
case Used in the switch conditional
catch Used in the try..catch statement
class Declare a class
clone Create a copy of an object
const Define a class constant
continue Jump to the next iteration of a loop
declare Set directives for a block of code
default Used in the switch statement
do Create a do...while loop
echo Output text
else Used in conditional statements
elseif Used in conditional statements
empty Check if an expression is empty
enddeclare End a declare block
endfor End a for block
endforeach End a foreach block
endif End an if or elseif block
endswitch End a switch block
endwhile End a while block
extends Extends a class or interface
final Declare a class, property or method as final
finally Used in the try...catch statement
fn Declare an arrow function
for Create a for loop
foreach Create a foreach loop
function Create a function
global Import variables from the global scope
goto Jump to a line of code
if Create a conditional statement
implements Implement an interface
include Embed code from another file
include_once Embed code from another file
instanceof Test an object's class
insteadof Resolve conflicts with traits
interface Declare an interface
isset Check if a variable exists and is not null
list Assigns array elements into variables
namespace Declares a namespace
new Creates an object
or A logical operator
print Output text
private Declare a property, method or constant as private
protected Declare a property, method or constant as protected
public Declare a property, method or constant as public
require Embed code from another file
require_once Embed code from another file
return Exit a function and return a value
static Declare a property or method as static
switch Create a switch block
throw Throw an exception
trait Declare a trait
try Create a try...catch structure
unset Delete a variable or array element
use Use a namespace
var Declare a variable
while Create a while loop or end a do...while loop
xor A logical operator
yield Used in generator functions
yield from Used in generator functions