Detailed explanation of how to call user-defined function instances in PHP

The following is a detailed analysis and introduction to the method of calling user-defined functions in php. Friends who need it can come and refer to it

Let’s put an example first:
The call_user_func function is similar to a special method of calling a function. The usage method is as follows:

function a($b,$c)    
{    
echo $b;    
echo $c;    
}    
call_user_func('a', "111","222");    
call_user_func('a', "333","444");    
//显示 111 222 333 444

It is strange to call the method inside the class. It actually uses

array. I don’t know how the developers thought about it. Of course, new is omitted, which is also full of novelty:

class
 a {    
function b($c)    
{    
echo $c;    
}    
}    
call_user_func(array("a", "b"),"111");    
//显示 111

The call_user_func_array function is very similar to call_user_func, except that the parameters are passed in a different way, so that the parameters The structure is clearer:

function a($b, $c)    
{    
echo $b;    
echo $c;    
}    
call_user_func_array('a', array("111", "222"));    
//显示 111 222

The call_user_func_array function can also call methods inside the class

Class ClassA    
{    
function bc($b, $c) {    
     $bc = $b + $c;    
echo $bc;    
}    
}    
call_user_func_array(array('ClassA','bc'), array("111", "222"));    
//显示 333

Both the call_user_func function and the call_user_func_array function support

references, which makes them similar to ordinary functions The calls tend to have consistent functions:

function a($b)    
{    
$b++;    
}    
$c = 0;    
call_user_func('a', $c);    
echo $c;//显示 1    
call_user_func_array('a', array($c));    
echo $c;//显示 2

Another: both the call_user_func function and the call_user_func_array function support references.

<?php
function increment(&$var)
{
    $var++;
}
$a = 0;
call_user_func(&#39;increment&#39;, $a);
echo $a; // 0
call_user_func_array(&#39;increment&#39;, array(&$a)); // You can use this instead
echo $a; // 1
?>

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