How to call user-defined function in PHP using call user func() function

This article mainly introduces how the call user func() function in PHP calls a custom defined function. Interested friends can refer to it. I hope it will be helpful to everyone.

The call_user_func function is similar to a special method of calling a function. The usage method is as follows:

<?php
function nowamagic($a,$b) 
{ 
 echo $a; 
 echo $b; 
} 
call_user_func(&#39;nowamagic&#39;, "",""); 
call_user_func(&#39;nowamagic&#39;, "",""); 
//显示  
?>

It is strange to call the method inside the class. It actually uses an array. I don’t know how the developer did it. Of course, new is omitted, which is quite innovative:

<?php
class a { 
 function b($c) 
 { 
  echo $c; 
 } 
} 
call_user_func(array("a", "b"),""); 
//显示 
?>

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

<?php
function a($b, $c) 
{ 
 echo $b; 
 echo $c; 
} 
call_user_func_array(&#39;a&#39;, array("", "")); 
//显示 
?>

The call_user_func_array function can also call methods inside the class:

<?php
Class ClassA 
{ 
function bc($b, $c) { 
  $bc = $b + $c; 
echo $bc; 
} 
} 
call_user_func_array(array(&#39;ClassA&#39;,&#39;bc&#39;), array("", "")); 
//显示 
?>

Both the call_user_func function and the call_user_func_array function support references, which makes them more functionally consistent with ordinary function calls:

<?php
function a($b) 
{ 
 $b++; 
} 
$c = ; 
call_user_func(&#39;a&#39;, $c); 
echo $c;//显示 
call_user_func_array(&#39;a&#39;, array($c)); 
echo $c;//显示 
?>
另外，call_user_func函数和call_user_func_array函数都支持引用。
view sourceprint?
<?php
function increment(&$var)
{
 $var++;
}
$a = ;
call_user_func(&#39;increment&#39;, $a);
echo $a; // 
call_user_func_array(&#39;increment&#39;, array(&$a)); // You can use this instead
echo $a; // 
?>

The following will introduce how to use call_user_func to call a custom function

Using the call_user_func function, you can call a custom function by passing in a string function, and it supports Quote.

1.mixed call_user_func ( callable $callback [, mixed $parameter [, mixed $... ]] )

Call the customization provided by the first parameter Function, the following parameters are the parameters of the custom function, and the result of the custom function is returned

function say($word)
{
 echo $word;
}
call_user_func('say', 'hello world'); //hello world
当然也可以调用类中的方法：
class A {
 function say($word = '')
 {
  echo $word;
 }
} 
$a = new A(); //注意，必须是要实例化的，除非是static
call_user_func(array($a, 'say'), 'hello world'); //hello world

2.mixed call_user_func_array (callable $callback, array $param_arr)

It is said that the call_user_func_array and call_user_func functions have the same function, but there are some differences when calling parameters:

function a($word)
{
 echo $word;
}
class A {
 function say($word = '')
 {
  echo $word;
 }
}
call_user_func_array('a', array('hello world')); //hello world
$a = new A(); //注意，必须是要实例化的，除非是static
call_user_func_array(array($a, 'say'), array('hello world')); //hello world

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's learning.

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