List of all PHP Keywords with the Outputs

List of all PHP Keywords with the Outputs. Keywords are words that operate some meaning. In the general use of PHP language, these words cannot be used as a constant, a class name, a variable name, a method name, etc. These keywords when used are automatically interpreted by PHP. These PHP keywords, when utilized with variable names, can be blended with the actual keywords. Therefore, these keywords should not be used as variable names.

List of all PHP keywords

abstract	and	Array()	as
break	callable	case	catch
class	clone	cost	continue
declare	default	die()	do
echo	else	elseif	empty
enddeclare	endfor	endforeach	endif
endswitch	endwhile	eval()	exit()
extends	final	finally	for
foreach	function	global	goto
if	implements	include	include_once
instanceof	insteadof	interface	isset()
list()	namespace()	new	or
print	private	protected	public
require	require_once	return	static
switch	throw	trait	try
unset()	use	var	while
yield	yield_from	xor

Abstract Keyword:

<?php
abstract class Code {
abstract protected function Methodlive();
public function show() {
echo '<br>'.$this->Methodlive();}}
class CodeOne extends Code {
protected function Methodlive() {
echo '<br>'.'This is abstract keyword';}}
$objOne = new CodeOne;
$objOne->show();
?>,

Output

This is abstract keyword

and Keyword:

<?php
$a = 20;
$b = 21;
if($a ==20  and  $b == 21) {
echo 'Output  :  True';}
else
{
  echo 'Output  : False';}
?>

Output

Output : True

array():

<?php
$directions  = array("a" => "sun", "b" => "set", "c" => "in", "d" => "west");
print_r($directions);
?>

Output

Array ( [a] => sun [b] => set [c] => in [d] => west )

as keyword:

<?php
$directions  = array("a" => "east", "b" => "west", "c" => "north", "d" => "south");
foreach($directions as $key=>$value) {
echo '<br>'. $key. '=>'.$value;
}?>

Output

a=>east
b=>west
c=>north
d=>south

break keyword:

<?php
$arr = array("Teacher", "Student", "Table", "Chair");
foreach($arr as $key=>$value) {
if($value  == 'Table') {
break ; }
echo '<br>'.$value;}
?>

Output

Teacher
Student

case Keyword:

<?php
$i = 0;
while($i<4) {
switch($i) {
case 0:
echo "<br>"."Zero";
break;
case 1:
echo "<br>"."One";
break;
case 2:
echo "<br>"."Two";
break;
default:
echo "<br>"."Default";}
$i++;}
?>

Output

Zero
One
Two
Default

catch Keyword:

<?php
function myFunction(){
try {
$num1 = 20;
$num2 = 5;
if($num1 / $num2) {
throw new Exception('Divide By Five');}
} catch (Exception $e) {
die($e->getMessage());
}}
myFunction();
?>

Output

Divide By Five

class Keyword:

<?php
class Class1{
var $str = 'List of all PHP Keywords';
public function displayMethod() {
echo $this->str;
}}
$obj = new Class1;
$obj->displayMethod();
?>

Output

List of all PHP Keywords

const keyword:

The const keyword is applied to determine the name with a value using an assignment operator like here.
const AGE= 39;
There is no $ sign at the opening of a constant name like a normal variable has.

default Keyword:

<?php
$fruits = 'Orange';
switch ($fruits) {
case 'Grapes':
echo "Grapes";
break;
case 'Guava':
echo "Guava";
break;
case 'Strawberry':
echo "Strawberry";
break;
default:
echo "Fruit is not Grapes, Guava or Strawberry ";
break;
}
?>

Output

Fruit is not Grapes, Guava or Strawberry

do Keyword:

<?php
$a = 5;
do { if($a > 5) {
echo 'a is greater than 5';}
else{ echo 'a is less than 5';}}
while ($a < 5);
?>

Output

a is less than 5

die() Keyword

<?php
$conn = mysqli_connect('localhost','root','','dbname');
if(!$conn) {
die("Unable to connect ");}
?>

Output

PHP Fatal error: Uncaught Error: Call to undefined function mysqli_connect() in /home/gygrX5/prog.php:2 Stack trace: #0 {main} thrown in /home/gygrX5/prog.php on line 2

echo Keyword

<?php
echo 'This is softcodeon! ';
$name = 'Prince Rauf';
echo 'My name is '. $name;
?>

Output

This is softcodeon! My name is Prince Rauf

else Keyword

<?php
$a = 5;
if ($a > 10) {
echo "a is greater than 20";}
else {
echo "a is not greater than 20";}
?>

Output

a is not greater than 20

elseif keyowrd:

<?php
$a = 10;
if ($a > 20) {
echo "a is greater than 20";
} elseif ($a == 20) {
echo "a is equal to 20";
} else {
echo "a is smaller than 20";
}
?>

Output

a is smaller than 20

empty Keyword:

<?php
$str = 'List of all PHP Keywords';
if(empty($str)) {
echo 'This is empty';} 
else {
echo $str;}
?>

Output

This is Soft CodeOn!

endfor Keyword:

<?php
for($i=0;$i<3;$i++) :
echo "<br/>".$i;
endfor;
?>

Output

0
1
2

endif keyword:

<?php
if ($a > 10):
echo "a is greater than 20";
elseif ($a >20) :
echo "a is equal to 20";
else:
echo "a is not equal to 20";
endif;
?>

Output

a is not equal to 20

endforeach Keyword:

<?php
$arr = array(10,9,8,7,6,5,4,3,2,1);
foreach ($arr as $key=>$value):
echo '<br>'.$value;
endforeach;
?>

Output

10
9
8
7
6
5
4
3
2
1

endswitch Keyowrd:

<?php
$fruits = 'Orange';
switch ($fruits):
case 'Grapes':
echo "Grapes";
break;
case 'Strawberry':
echo "Strawberry";
break;
case 'Guava':
echo "Guava";
break;
default:
echo "Fruit is not Grapes, Strawberry or Guava ";
break;
endswitch;
?>

Output

Fruit is not Grapes, Strawberry or Guava

endwhile keyword:

<?php
$i = 1;
while($i<4):
echo "<br>".$i;
$i++;
endwhile;
?>

Output

1
2
3

eval() keyword:

<?php
$string1 = 'List of all PHP Keywords';
$string2 = 'Prince Rauf';
$string = 'Softcodeon $string1 .  My name is $string2';
echo "<br>".$string;
eval("\$string = \"$string\";");
echo "<br>".$string;
?>

Output

List of all PHP Keywords$string1 . My name is $string2 Softcodeon Softcodeon . My name is Prince Rauf

exit() Keyword:

This keyword when found in a script, ends the execution of the script.

final Keyword:

<?php
class MyClass {
var $string = 'Learn PHP';
final public function display() {
echo $this->string;
}}
class ExtendClass extends MyClass {
public function display() {
echo 'Softcodeon!';
}}
$obj1 = new ExtendClass;
$obj1->display();
?>

Output

PHP Fatal error: Cannot override final method MyClass::display() in /home/6gQY2c/prog.php on line 10

catch Keyword:

<?php
try {
$num1 = 20;
$num2 = 5;
if($num1 / $num2) {
throw new Exception('Divide By Five');}
} catch (Exception $e) {
echo '<br>'.$e->getMessage();}
?>

Output

Divide By Five

for Keyword:

<?php
for($i=0; $i<10; $i++) {
if($i == 5) {
break;}
echo '<br>'.$i;}
?>

Output

0
1
2
3
4

foreach Keyword:

<?php
$array = array(10,20,30,40,50);
foreach($array as $value) {
echo '<br>'.$value/10;}
?>

Output

1
2
3
4
5

function() Keyword:

<?php
function calSum($a , $b) {
$c = $a + $b;
return $c;
}
$result = calSum(20 , 30);
echo '<br> The sum  :  '.$result;
?>

Output

The sum : 50

global Keyword:

<?php
$a = 5;
$b = 10;
function fun() {
global $a;
global $b;
$sum = $a + $b;
return $sum;
}
$f = fun();
echo 'The sum is '.$f;
?>

Output

The sum is 15

if Keyword:

<?php
$sum = 20;
if($sum == 20) {
echo 'Sum is 20';
} else {
echo 'Sum is not 20';
}
?>

Output

Sum is 20

implements Keyword:

<?php
interface One
{
public function first();
}
class MyClass implements One {
public function first() {
echo 'List of all PHP Keywords, This is the First function';
}
}
$obj = new MyClass;
echo $obj->first();
?>

Output

This is the First function

include Keyword:

file.php

<?php
$a = 'Earth';
$b = 'Sky';
?>

index.php

<?php
include 'file.php';
echo $a . ' is '. $b. ' in Shape';
?>

instanceOf Keyword:

<?php
class MyClass
{
public function MyClassMethod(){
echo 'List of all PHP Keywords!';
}}
class ExtendedClass extends MyClass
{
public function ExtendedClassMethod(){
echo 'Have a Nice Day!';
}}
$obj1 = new ExtendedClass;
var_dump($obj1 instanceOf ExtendedClass);
?>

Output

bool(true)

isset Keyword:

<?php
$stringOne = '';
var_dump(isset($stringOne));
$stringTwo = NULL;
var_dump(isset($stringTwo));
?>

Output

bool(true) bool(false)

list Keyword:

<?php
$names = array('Rauf','Ali','Ahmad');
list($person1, $person2, $person3) = $names;
echo "$person1, $person2 and $person3 are friends";
?>

Output

Rauf, Ali and Ahmad are friends

new Keyword:

<?php
class MyClass
{
public function score($name, $subject, $marks) {
echo "$name scored $marks marks in $subject";
}}
$obj = new MyClass;
$obj->score('Rauf','Computer',90);
?>

Output

Rauf scored 90 marks in Computer

print Keyword:

<?php
$str = "List of PHP Keyword";
print($str);
$stringOne = "Rauf, ";
$stringTwo = "How are you?";
print "<br>"."Hello $stringOne $stringTwo";
?>

Output

List of PHP Keyword
Hello Rauf, How are you?

private Keyword:

<?php
class MyClass
{
private $str = 'Private';
function PrivateMethod()
{
echo 'In '. $this->str. ' Method';
}}
$obj = new MyClass();
$obj->PrivateMethod(); 
?>

Output

In Private Method

public Keyword:

<?php
class MyClass
{
public $str = 'Public';
function PublicMethod()
{
echo 'In '. $this->str. ' Method';
}}
$obj = new MyClass();
$obj->PublicMethod(); 
?>

Output

In Public Method

protected Keyword:

<?php
class MyClass
{
protected $str = 'Protected';
function ProtectedMethod()
{
echo 'In '. $this->str. ' Method';
}}
$obj = new MyClass();
$obj->ProtectedMethod(); 
?>

Output

In Protected Method

return Keyword:

<?php
function sum() {
$a = 20;
$b = 30;
$c = $a +$b;
return $c;
}
$result = sum();
echo 'Sum : ' . $result;
?>

Output

Sum : 50

var Keyword:

<?php
class MyClass
{
var $str = 'PHP Programming';
public function displayMsg() {
echo $this->str;
}
}
$obj = new MyClass;
$obj->displayMsg();
?>

Output

PHP Programming

while Keyword:

<?php
$i = 0;
while ($i<5) {
echo '<br>'. $i;
$i++;
}
?>

Output

0
1
2
3
4

Conclusion

In this article, you have to learn about keywords in PHP with outputs. These examples explain the usage of each of the keyword in PHP.

2 Comments

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