Introduction des mots-clés PHP

Les mots-clés sont les mots qui ont un sens. Dans l'utilisation régulière du langage PHP, ces mots ne peuvent pas être utilisés comme constantes, nom de variable, nom de méthode, nom de classe, etc. Ces mots-clés lorsqu'ils sont utilisés sont automatiquement compris par PHP. Ces mots clés PHP, lorsqu'ils sont utilisés avec des noms de variables, peuvent être confondus avec les mots clés réels. Par conséquent, ces mots clés ne doivent pas être utilisés comme noms de variable.

Liste de tous les mots clés PHP

Mot-clé: résumé

Code:

<_?php
//example to demonstrate abstract keyword
abstract class Program (
abstract protected function MethodOne();
public function display() (
echo '
'.$this->MethodOne();
)
)
class ProgramOne extends Program (
protected function MethodOne() (
echo '
'.'In MethodOne';
)
)
$objOne = new ProgramOne;
$objOne->display();
?>,

Production:

Mot-clé: et

Code:

<_?php
//example to demonstrate and keyword
$a = 10;
$b = 11;
if($a ==10 and $b == 11) (
echo 'Result : True';
)
else
(
echo 'Result : False';
)
?>

Production:

Mot-clé: tableau ()

Code:

<_?php
//example to demonstrate array keyword
$directions = array("e" => "east", "w" => "west", "n" => "north", "s" => "south");
print_r($directions);
?>

Production:

Mot-clé: as

Code:

<_?php
//example to demonstrate array keyword
$directions = array("e" => "east", "w" => "west", "n" => "north", "s" => "south");
foreach($directions as $key=>$value) (
echo '
'. $key. '=>'.$value;
)
?>

Production:

Mot-clé: pause

Code:

<_?php
//use of break keyword without optional argument
$arr = array("water", "sky", "try", "sand");
foreach($arr as $key=>$value) (
if($value == 'try') (
break ; // can use break 1 also
)
echo '
'.$value;
)
?>

Production:

Mot-clé: cas

Code:

<_?php
//example to demonstrate case keyword
$i = 1;
while($i<5) (
switch($i) (
case 1:
echo "
"."One";
break;
case 2:
echo "
"."Two";
break;
case 3:
echo "
"."Three";
break;
default:
echo "
"."Default";
)
$i++;
)
?>

Production:

Mot-clé: catch

Code:

<_?php
//example to demonstrate catch keyword
function Operation()
(
try (
$num1 = 10;
$num2 = 0;
if($num1 / $num2) (
throw new Exception('Divide By Zero');
)
) catch (Exception $e) (
die($e->getMessage());
)
)
Operation();
?>

Production:

Mot-clé: classe

Code:

<_?php
//example to demonstrate class keyword
class ClassOne(
var $str = 'Hello World';
public function displayMethod() (
echo $this->str;
)
)
$obj = new ClassOne;
$obj->displayMethod();
?>

Production:

Mot-clé: const

le mot clé const est utilisé pour définir le nom avec une valeur en utilisant l'opérateur d'affectation comme ci-dessous

const AGE = 29;

Il n'y a pas de signe $ au début d'un nom constant comme une variable normale.

Mot-clé: par défaut

Code:

<_?php
// example to demonstrate default keyword
$fruits = 'Cherries';
switch ($fruits) (
case 'Apple':
echo "Apple";
break;
case 'Banana':
echo "Banana";
break;
case 'Papaya':
echo "Papaya";
break;
default:
echo "Fruit is not Apple, Banana or Papaya ";
break;
)
?>

Production :

Mot-clé: faire

Code:

<_?php
// example to demonstrate do keyword
$x = 2;
do (
if($x > 2)
(
echo 'x is greater than 2';
)
else(
echo 'x is less than 2';
)
) while ($x < 2);
?>

Production:

Mot-clé: die ();

Code:

<_?php
//example to demonstrate die keyword
$conn = mysqli_connect('localhost', 'root', '', 'dbname');
if(!$conn) (
die("Unable to connect ");
)
?>

Production:

Mot-clé: écho

Code:

<_?php
// example to demonstrate echo keyword
echo 'Hello! ';
$name = 'John Doe';
echo 'My name is '. $name;
?>

Production:

Mot-clé: autre

Code:

<_?php
// example to demonstrate else keyword
$a = 10;
if ($a > 5) (
echo "a is greater than 10";
) else (
echo "a is not greater than 10";
)
?>

Production:

Mot-clé: elseif

Code:

<_?php
// example to demonstrate elseif keyword
$a = 10;
if ($a > 10) (
echo "a is greater than 10";
) elseif ($a == 10) (
echo "a is equal to 10";
) else (
echo "a is smaller than 10";
)
?>

Production :

Mot-clé: vide

Code:

<_?php
// example to demonstrate empty keyword
$str = 'Hello World!';
if(empty($str)) (
echo 'Variable is empty';
) else (
echo $str;
)
?>

Production:

Mot-clé: endfor

Code:

<_?php
// example to demonstrate endfor keyword
for($i=0;$i<5;$i++) :
echo "
".$i;
endfor;
?>

Production:

Mot-clé: endif

Code:

<_?php
// example to demonstrate endif keyword
if ($a > 10):
echo "a is greater than 10";
elseif ($a >10) :
echo "a is equal to 10";
else:
echo "a is not equal to 10";
endif;
?>

Production:

Mot-clé: endforeach

Code:

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

Production:

Mot-clé: endswitch

Code:

<_?php
// example to demonstrate endswitch keyword
$fruits = 'Cherries';
switch ($fruits):
case 'Apple':
echo "Apple";
break;
case 'Banana':
echo "Banana";
break;
case 'Papaya':
echo "Papaya";
break;
default:
echo "Fruit is not Apple, Banana or Papaya ";
break;
endswitch;
?>

Production:

Mot-clé: fin

Code:

<_?php
// example to demonstrate endwhile keyword
$i = 0;
while($i<5):
echo "
".$i;
$i++;
endwhile;
?>

Production:

Mot-clé: eval ()

Code:

<_?php
//example to demonstrate eval keyword
$string1 = 'World';
$string2 = 'John Doe';
$string = 'Hello $string1 . My name is $string2';
echo "
".$string;
eval("\$string = \"$string\";");
echo "
".$string;
?>

Production:

Mot-clé: exit ()

Ce mot-clé lorsqu'il est rencontré dans un script, met fin à l'exécution du script.

Mot-clé: étend ()

Code:

<_?php
//example to demonstrate extends keyword
class ParentClass (
var $string = 'PHP';
public function display() (
echo $this->string;
)
)
class ExtendClass extends ParentClass (
public function display() (
echo 'Hello World!';
)
)
$obj1 = new ExtendClass;
$obj1->display();
?>

Production:

Mot-clé: final

Code:

<_?php
//example to demonstrate final keyword
class ParentClass (
var $string = 'PHP';
final public function display() (
echo $this->string;
)
)
class ExtendClass extends ParentClass (
public function display() (
echo 'Hello World!';
)
)
$obj1 = new ExtendClass;
$obj1->display();
?>

Production :

Mot-clé: catch

Code:

<_?php
//example to demonstrate catch keyword
try (
$num1 = 10;
$num2 = 0;
if($num1 / $num2) (
throw new Exception('Divide By Zero');
)
) catch (Exception $e) (
echo '
'.$e->getMessage();
)
?>

Production:

Mot-clé: pour

Code:

<_?php
// example to demonstrate for keyword
for($i=0; $i<10; $i++) (
if($i == 5) (
break;
)
echo '
'.$i;
)
?>

Production :

Mot-clé: foreach

Code:

<_?php
// example to demonstrate foreach keyword
$array = array(10, 20, 30, 40, 50);
foreach($array as $value) (
echo '
'.$value/10;
)
?>

Production:

Mot-clé: fonction ()

Code:

<_?php
function calSum($a, $b) (
$c = $a + $b;
return $c;
)
$result = calSum(10, 20);
echo '
The sum : '.$result;
?>

Production:

Mot-clé 34: global

Code:

<_?php
//example to demonstrate global keyword
$a = 10;
$b = 20;
function fun() (
global $a;
global $b;
$result = $a + $b;
return $result;
)
$f = fun();
echo 'The result is '.$f;
?>

Production:

Mot-clé: si

Code:

<_?php
// example to demonstrate if keyword
$sum = 10;
if($sum == 10) (
echo 'Sum is 10';
) else (
echo 'Sum is not 10';
)
?>

Production:

Mot-clé: implémente

Code:

<_?php
//example to demonstrate interface keyword
interface One
(
public function first();
)
class MainClass implements One (
public function first() (
echo 'This is the First function';
)
)
$obj = new MainClass;
echo $obj->first();
?>

Production :

Mot-clé: inclure

Code:

file.php

<_?php
//example to demonstrate include keyword
$a = 'The Earth';
$b = 'Round';
?>

index.php

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

Mot-clé: include_once

Code:

file.php

<_?php
//example to demonstrate include_once keyword
$a = 'The Earth';
$b = 'Round';
?>

index.php

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

Production:

Mot-clé: instanceOf

Code:

<_?php
//example to demonstrate instanceOf keyword
class MainClass
(
public function MainCLassMethod()(
echo 'Hello World!';
)
)
class ExtendedClass extends MainClass
(
public function ExtendedClassMethod()(
echo 'Have a Nice Day!';
)
)
$obj1 = new ExtendedClass;
var_dump($obj1 instanceOf ExtendedClass);
?>

Production:

Mot-clé: interface

Code:

<_?php
//example to demonstrate interface keyword
interface One
(
public function one();
)
interface Two
(
public function two();
)
class MainClass implements One, Two (
public function one() (
echo '
This is the one function';
)
public function two() (
echo '
This is the two function';
)
)
$obj = new MainClass;
echo $obj->one();
echo $obj->two();
?>

Production:

Mot-clé: isset

Code:

<_?php
//example to demonstrate isset keyword
$stringOne = '';
var_dump(isset($stringOne));
$stringTwo = NULL;
var_dump(isset($stringTwo));
?>

Production :

Mot-clé: liste

Code:

<_?php
//example to demonstrate list keyword
$names = array('Ram', 'Mohan', 'Raghav');
list($person1, $person2, $person3) = $names;
echo "$person1, $person2 and $person3 are friends";
?>

Production:

Mot-clé: nouveau

Code:

<_?php
//example to demonstrate new keyword
class Student
(
public function score($name, $subject, $marks) (
echo "$name scored $marks marks in $subject";
)
)
$obj = new Student;
$obj->score('Sunil', 'Maths', 90);
?>

Production:

Mot-clé: ou

Code:

<_?php
//example to demonstrate or keyword
$a = 10;
$b = 11;
if($a ==10 or $b == 12) (
echo 'Result : True';
)
else
(
echo 'Result : False';
)
?>

Production :

Mot-clé: imprimer

Code:

<_?php
//example to demonstrate print keyword
$str = "PHP Programming";
print($str);
$stringOne = "Shyam, ";
$stringTwo = "How are you?";
print "
"."Hello $stringOne $stringTwo";
?>

Production :

Mot-clé: privé

Code:

<_?php
//example to demonstrate private keyword
class MainClass
(
private $str = 'Private';
function PrivateMethod()
(
echo 'In '. $this->str. ' Method';
)
)
$obj = new MainClass();
$obj->PrivateMethod(); //Shows Private Method
?>

Production:

Mot-clé: public

Code:

<_?php
//example to demonstrate public keyword
class MainClass
(
public $str = 'Public';
function PublicMethod()
(
echo 'In '. $this->str. ' Method';
)
)
$obj = new MainClass();
$obj->PublicMethod(); //Shows Public Method
?>

Production:

Mot-clé: protégé

Code:

<_?php
//example to demonstrate protected keyword
class MainClass
(
protected $str = 'Protected';
function ProtectedMethod()
(
echo 'In '. $this->str. ' Method';
)
)
$obj = new MainClass();
$obj->ProtectedMethod(); //Shows Protected Method
?>

Production:

Mot-clé: retour

Code:

<_?php
//example to demonstrate return keyword
function sum() (
$a = 10;
$b = 20;
$c = $a +$b;
return $c;
)
$result = sum();
echo 'Sum : ' . $result;
?>

Production:

Mot-clé: commutateur

Code:

<_?php
//example to demonstrate switch keyword
$i= 3;
switch($i) (
case 1:
echo "
"."One";
break;
case 2:
echo "
"."Two";
break;
case 3:
echo "
"."Three";
break;
default:
echo "
"."Default";
)
?>

Production:

Mot-clé: jeter

Code:

<_?php
//example to demonstrate throw keyword
function division($x, $y) (
try (
if($y == 0) (
throw new Exception('Divide By Zero');
)
)
catch (Exception $e) (
echo '
'.$e->getMessage();
)
)
division(10, 0);
?>

Production:

Mot-clé: essayer

Code:

<_?php
//example to demonstrate try keyword
try(
$arr = array();
$arr_length = count($arr);
if($arr_length == 0) (
throw new Exception('Error : Empty Array!');
)
else (
echo 'Array found';
print_r($arr);
)
)
catch(Exception $e) (
echo '
'.$e->getMessage();
)
?>

Production:

Mot-clé: unset

Code:

<_?php
//example to demonstrate unset keyword
echo 'Hello World!'.'
';
$a = 10;
echo $a;
unset($a);
// echo $a; //this line when uncommented shows error : Undefined variable, as the variable is unset
?>

Production:

Mot-clé: var

Code:

<_?php
//example to demonstrate var keyword
class MainClass
(
var $str = 'PHP Programming';
public function displayMsg() (
echo $this->str;
)
)
$obj = new MainClass;
$obj->displayMsg();
?>

Production:

Mot-clé: tout

Code:

<_?php
//example to demonstrate while keyword
$i = 0;
while ($i<10) (
echo '
'. $i;
$i++;
)
?>

Production:

Conclusion

Dans cet article, vous découvrirez les mots clés en PHP avec des exemples. Ces exemples expliquent l'utilisation de chacun des mots clés en PHP.

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