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PHP final Keyword
Introduction
Using final keyword in the definition of an instance method in a PHP class prevents it from being overridden by child class. Similarly, if final is used in definition of class itself, such a class cannot be extended.
Syntax
final class myclass {}
class myclass{
final method mymethod(){}
}final method example
In following example, attempt tooverride final method results in error
Example
<?php
class parentclass{
final function test(){
echo "final method in parent class";
}
}
class childclass extends parentclass{
function test(){
echo "overriding final method in parent class";
}
}
$obj=new childclass();
$obj->test();
?>Output
Output shows following error message
PHP Fatal error: Cannot override final method parentclass::test() in line 16
final class example
Similarly a final class can't be inherited from as following example shows
Example
<?php
final class parentclass{
final function test(){
echo "final method in parent class";
}
}
class childclass extends parentclass{
function test(){
echo "overriding final method in parent class";
}
}
$obj=new childclass();
$obj->test();
?>Output
Output shows following error message
PHP Fatal error: Class childclass may not inherit from final class (parentclass) in line 16
Updated on: 18-Sep-2020
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