PHP load classes are used for declaring its object etc. in object oriented applications. PHP parser loads it automatically, if it is registered with spl_autoload_register() function. PHP parser gets the least chance to load class/interface before emitting an error.
Syntax:
spl_autoload_register(function ($class_name) {
include $class_name . '.php';
});
The class will be loaded from its corresponding “.php” file when it comes into use for the first time.
Autoloading
Example:
PHP
<?php spl_autoload_register(function ($class_name) { include $class_name . '.php'; }); $obj = new mytest1(); $obj2 = new mytest2(); echo "Objects of mytest1 and mytest2 " + "class created successfully"; ?> |
Output:
Objects of test1 and test2 class created successfully.
Note: If the corresponding “.php” file having class definition is not found, the following error will be displayed.
Warning: include(): Failed opening 'test10.php' for inclusion (include_path='C:\xampp\php\PEAR') in line 4 PHP Fatal error: Uncaught Error: Class 'test10' not found.
Autoloading with exception handling
Example:
PHP
<?php spl_autoload_register(function($className) { $file = $className . '.php'; if (file_exists($file)) { echo "$file included\n"; include $file; } else { throw new Exception("Unable to load $className."); } }); try { $obj1 = new test1(); $obj2 = new test10(); } catch (Exception $e) { echo $e->getMessage(), "\n"; } ?> |
Output:
Unable to load test1.
