Note: Unlike other object-oriented programming languages, in PHP, a class cannot use the final modifier on an attribute variable.
If you want to declare a property as a constant, you can use the Const keyword, and you do not need to use the dollar sign as a variable name prefix, nor do you need to use the access permission modifier. A constant means that although the variable can be accessed, the value of the variable cannot be modified. For example, the following code declares a constant property Con_var:
Copy Code code as follows:
<?php
Class foo{
Const Con_var= "The value of a constant property cannot be modified <br/>";
Public Function method_a () {
Echo (Self::con_var);
}
}
Echo (Foo::con_var);
$myFoo =new Foo ();
Echo ($myFoo->method_a ());
?>
Constant properties cannot use object access, only class access, and within the class ontology you can use "self:: constant name" to use "class name:: Constant Name" Outside the class ontology.
