Definition¶
A definition is the description of a particular constant, function, method, property, class, trait, interface or enum.
A variable also has a definition, also called an initialisation: variables have no formal definition. They use an unconditional assignation to do so.
The definition is also called a declaration. The declaration must happen before usage.
Definitions happens in custom code, in libraries or in PHP extensions.
There are functions dedicated to listing defined elements: get_declared_constants()
, get_declared_traits()
, get_declared_interfaces()
, get_declared_classes()
, get_class_vars()
and get_class_methods()
.
<?php
//function declaration
function foo() {
print 'OK';
}
// call to the function foo
foo();
?>
Related : Call