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Three commonly used functions in the PHP SPL standard library

墨辰丷

Release： 2023-03-31 12:30:01

Original

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This article mainly introduces the commonly used functions in the PHP SPL standard library. This article focuses on the three functions of spl_autoload_extensions(), spl_autoload_register(), and spl_autoload(). Friends in need can refer to it

The PHP SPL standard library provides some functions for processing such as automatic loading, iterator processing, etc.

spl_autoload_extensions() adds file extensions that can be loaded by spl_autoload()
spl_autoload_register() registers the function into the SPL __autoload function stack.

The code is as follows:

/*test1.php*/
<?php
class Test1
{
}
 
/*test2.lib.php*/
<?php
class Test2
{
}
 
/*test.php*/
<?php
//设置可加载类的文件扩展名
spl_autoload_extensions(".php,.inc.php,.class.php,.lib.php");
//设置include_path,autoload会在这些path中去寻找类文件,可通过PATH_SEPARATOR添加多个path
set_include_path(get_include_path().PATH_SEPARATOR.&#39;libs/&#39;);
//不提供参数，默认实现函数是spl_autoload()
spl_autoload_register();
 
$test1 = new Test1();
$test2 = new Test2();
spl_autoload()它是__autoload()的默认实现，它会去include_path中加载文件(.php/.inc)

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The code is as follows:

/*test1.php*/
<?php
class Test1
{
}
 
/*test.php*/
<?php
set_include_path(get_include_path().PATH_SEPARATOR.&#39;libs/&#39;);
spl_autoload(&#39;test1&#39;);
$test1 = new Test1();
spl_autoload_call()调用所有spl_autoload_register注册函数来加载文件

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The code is as follows:

/*test1.php*/
<?php
class Test
{
    public function getFilename()
    {
        echo &#39;test1.php&#39;;
    }
}
 
/*test2.lib.php*/
<?php
class Test
{
    public function getFilename()
    {
        echo &#39;test2.lib.php&#39;;
    }
}
 
/*test.php*/
<?php
 
function loader($classname)
{
    if($classname == &#39;Test1&#39;) {
        require __DIR__ . &#39;/test1.php&#39;;
    }
    if($classname == &#39;Test2&#39;) {
        require __DIR__ . &#39;/test2.lib.php&#39;;
    }
}
 
spl_autoload_register(&#39;loader&#39;);
spl_autoload_call(&#39;Test2&#39;);
 
 
$test = new Test();
$test->getFilename(); //test2.lib.php

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Other SPL function introduction:
class_implements — Returns the specified class All interfaces implemented.
class_parents — Returns the parents of the specified class.
class_uses — Return the traits used by the given class
iterator_apply — Call a user-defined function for each element in the iterator
iterator_count — Count the number of elements in the iterator
iterator_to_array — Will The elements in the iterator are copied to the array
spl_autoload_functions — Returns all registered __autoload() functions
spl_autoload_unregister — Unregisters registered __autoload() functions
spl_classes — Returns all available SPL classes
spl_object_hash — Returns the hash id of the specified object

If iterator related functions are used:

The code is as follows:

$iterator  = new  ArrayIterator (array( &#39;recipe&#39; => &#39;pancakes&#39; ,  &#39;egg&#39; ,  &#39;milk&#39; ,  &#39;flour&#39; ));
 
print_r(iterator_to_array($iterator)); //将迭代器元素转化为数组
echo iterator_count($iterator); //计算迭代器元素的个数
print_r(iterator_apply($iterator, &#39;print_item&#39;, array($iterator)));//为迭代器每个元素调用自定义函数
 
 
function print_item(Iterator $iterator)
{
    echo  strtoupper ( $iterator -> current ()) .  "\n" ;
    return  TRUE ;
}

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