PHP get_declared_classes() Function

What is PHP get_declared_classes() Function?

If you want to see all the classes used in your current script, use PHP get­_declared_classes() function. The output includes 2 types of classes-1) User defined classes and 2) built-in PHP classes.

Syntax:

get­_declared_classes()

Parameters:

The Function has no parameter.

Return Values:

This function returns an indexed array whose each element is a class name. This function returns lots of built-in classes.

Examples:

Example 1:

<pre>
<?php
class Human {}
class Male {}
class Female {}
echo "This script includes the following classes-" . "<br />";
print_r(get_declared_classes());
class Tree {}
?>
</pre>

Output:

This script includes the following classes-
Array
(
    [0] => InternalIterator
    [1] => Exception
    [2] => ErrorException
    [3] => Error
    [4] => CompileError
    [5] => ParseError
    [6] => TypeError
          ….
    [171] => Human
    [172] => Male
    [173] => Female
    [174] => Tree
)

Explanation:

The function includes lots of built-in classes including the first 6 ones.

Notes on get_declared_classes() Function:

• If you want to check whether a class has been declared in your current script, use in_array() function in the output of this function. Check example below-

<?php
class Human {}
class Male {}
class Female {}
if(in_array('Male',get_declared_classes())){
    echo "Class 'Male' declared.";
}else{
    echo "Class 'Male' not declared.";
}
?>

Output:

Class 'Male' declared.

• The function doesn’t include classes from autoloader until it is instantiated or required explicitly.
• Class names are case-sensitive, meaning, the returned class names are same as those were defined.

PHP Version Support:

PHP 4, PHP 5, PHP 7, PHP 8

Summary: PHP get_declared_classes() Function

get_declared_classes() is a class/object type function in PHP. Use this function to see list of classes used in a script.

Reference:

https://www.php.net/manual/en/function.get-declared-classes.php