Introduction to common functions in the php spl standard library

Introduction to common functions in the php spl standard library

This article mainly introduces common functions in the php spl standard library. This article focuses on three functions: spl_autoload_extensions (), spl_autoload_register (), and spl_autoload (). For more information, see

The php spl Standard Library provides functions for processing, such as automatic loading and iterator processing.

Spl_autoload_extensions () Add the file extension that spl_autoload () can load

Spl_autoload_register () registers the function to the SPL _ autoload function stack.

Copy the Code as follows:

/* Test1.php */

　　

Class Test1

{

}

/* Test2.lib. php */

　　

Class Test2

{

}

/* Test. php */

　　

// Set the file extension of the loadable class

Spl_autoload_extensions (". php,. inc. php,. class. php,. lib. php ");

// Set include_path. autoload searches for class files in these paths. You can use PATH_SEPARATOR to add multiple paths.

Set_include_path (get_include_path (). PATH_SEPARATOR. 'libs /');

// No parameters are provided. The default function is spl_autoload ()

Spl_autoload_register ();

$ Test1 = new Test1 ();

$ Test2 = new Test2 ();

Spl_autoload () is the default Implementation of _ autoload (). It Loads files (. php/. inc) in include_path)

Copy the Code as follows:

/* Test1.php */

　　

Class Test1

{

}

/* Test. php */

　　

Set_include_path (get_include_path (). PATH_SEPARATOR. 'libs /');

Spl_autoload ('test1 ');

$ Test1 = new Test1 ();

Spl_autoload_call () calls all spl_autoload_register registration functions to load files

Copy the Code as follows:

/* Test1.php */

　　

Class Test

{

Public function getFilename ()

{

Echo 'test1. php ';

}

}

/* Test2.lib. php */

　　

Class Test

{

Public function getFilename ()

{

Echo 'test2. lib. php ';

}

}

/* Test. php */

　　

Function loader ($ classname)

{

If ($ classname = 'test1 '){

Require _ DIR _. '/test1.php ';

}

If ($ classname = 'test2 '){

Require _ DIR _. '/test2.lib. php ';

}

}

Spl_autoload_register ('loader ');

Spl_autoload_call ('test2 ');

$ Test = new Test ();

$ Test-> getFilename (); // test2.lib. php

Other SPL functions:

Class_implements-return all interfaces implemented by the specified class.

Class_parents-return the parent class of the specified class.

Class_uses-Return the traits used by the given class

Iterator_apply-calls a user-defined function for each element in the iterator

Iterator_count-calculate the number of elements in the iterator

Iterator_to_array-copy the elements in the iterator to the array

Spl_autoload_functions-returns all registered _ autoload () functions.

Spl_autoload_unregister-deregister the registered _ autoload () function

Spl_classes-returns all available SPL classes

Spl_object_hash-return the hash id of the specified object

For example, use iterator functions:

Copy the Code as follows:

$ Iterator = new ArrayIterator (array ('receiver' => 'pancaes', 'egg', 'milk', 'flour '));

Print_r (iterator_to_array ($ iterator); // convert the iterator element into an array

Echo iterator_count ($ iterator); // calculates the number of iterator Elements

Print_r (iterator_apply ($ iterator, 'print _ item', array ($ iterator); // calls a custom function for each element of the iterator

Function print_item (Iterator $ iterator)

{

Echo strtoupper ($ iterator-> current (). "\ n ";

Return TRUE;

}