The three most common functions in PHP SPL standard library

This article mainly introduces the common functions introduced in PHP SPL standard library, this article emphatically explains the Spl_autoload_extensions (), Spl_autoload_register (), Spl_autoload () three functions, A friend you need can refer to the following

The PHP SPL standard library provides functions for handling such as automatic loading, iterator processing, and so on.

Spl_autoload_extensions () add spl_autoload () to load the file name extension
Spl_autoload_register () registers the function into the SPL __autoload function stack.

The code is as follows:

/*test1.php*/<?phpclass test1{}/*test2.lib.php*/<?phpclass test2{}/*test.php*/<?php//Set the file name extension of the Loadable class Spl_ Autoload_extensions (". php,.inc.php,.class.php,.lib.php");//settings Include_path,autoload will find the class file in these paths, which can be obtained by path_ Separator Add multiple Pathset_include_path (Get_include_path (). Path_separator. ' libs/');//do not provide parameters, the default implementation function is Spl_autoload () spl_autoload_register (); $test 1 = new Test1 (), $test 2 = new Test2 (); Spl_autoload () It is the default implementation of __autoload () and it will go to include_path to load the file (. php/.inc)

The code is as follows:

/*test1.php*/<?phpclass test1{}/*test.php*/<?phpset_include_path (Get_include_path (). Path_separator. ' libs/'); Spl_autoload (' test1 '); $test 1 = new Test1 (); Spl_autoload_call () Call all Spl_autoload_ Register registration function to load files

The code is as follows:

/*test1.php*/<?phpclass test{public    function GetFileName ()    {        echo ' test1.php ';    }}/* Test2.lib.php*/<?phpclass test{public    function GetFileName ()    {        echo ' test2.lib.php ';    }}/* test.php*/<?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 are described:
class_implements-returns all interfaces implemented by the specified class.
class_parents-returns 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-calculating the number of elements in an iterator
iterator_to_array-copying elements from an iterator to an array
spl_autoload_functions-returns all registered __autoload () functions
spl_autoload_unregister-Unregister a registered __autoload () function
spl_classes-return all available SPL classes
spl_object_hash-returns the hash ID of the specified object

such as the iterator correlation function uses:

The code is as follows:

$iterator  = new  arrayiterator (Array (' recipe ' = ' pancakes ',  ' egg ',  ' milk ',  ' flour ')); print _r (Iterator_to_array ($iterator)); Converts an iterator element to an array of echo iterator_count ($iterator); Computes the number of iterator elements Print_r (iterator_apply ($iterator, ' Print_item ', Array ($iterator)));//Calling Custom function functions for each element of an iterator  Print_item (Iterator $iterator) {    echo  strtoupper ($iterator-current ()).  " \ n ";    return  TRUE;}

Summary : The above is the entire content of this article, I hope to be able to help you learn.

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