PHP uses Func_get_args () and Func_num_args () functions to implement function overloading

These two functions implement the overload of the function!!

1. Default parameters

From this above can be seen, if a function inside, not the necessary parameters, add the corresponding default value, you can complete the corresponding function.

The code is as follows	Copy Code
function Overloadfun ($param 1, $param 2 = ' 1 ', $param 3 = True) { Do something }

Using Functions Func_get_args () and Call_user_func_array ()

PHP Code:

The code is as follows	Copy Code
function rewrite () { $args = Func_get_args (); if (Func_num_args () = = 1) { Func1 ($args [0]); else if (func_num_args () = = 2) { Func2 ($args [0], $args [1]); } } function Func1 ($arg) { echo $arg; } function Func2 ($arg 1, $arg 2) { echo $arg 1, ', $arg 2; } Rewrite (' PHP '); Call Func1 Rewrite (' PHP ', ' it '); Call Func2

2. Use the default value to get the results you want based on the input:

The code is as follows	Copy Code
function Test ($name = "Xiao Li", $age = "23") { echo $name. "". $age; } Test (); echo "<br/>"; Test ("a"); echo "<br/>"; Test ("A", "B");

3. Use the __call ($name, $arg) function for processing.

The code is as follows

Copy Code

<?php     class overload{    function __call ($name, $args)    { & nbsp if ($name = = ' Overloadfun ')   {    switch (count ($args))    {     Case 0: $this->overloadfun0 ();     Case 1: $this->overloadfun1 ($args [0]);     Case 2: $this->overloadfun2 ($args [0], $args [1]);     Default://do something       break;   }     }       function overloadFun0 ()    {   echo 0;   }       function overloadFun1 ($var 1)    {   echo $var 1;< br>   } function overloadFun2 ($var 1, $var 2) { echo $var 1+ $var 2; } } $test =new overload (); $test->overloadfun (). " <br/> ". $test->overloadfun (1). " <br/> ". $test->overloadfun (1,2). " <br/> "; ?>

With this method we can use them to implement simple function overload, but one thing to note is that PHP as a weak type language, itself can not be as strong as the Java, C + +, the direct implementation of the overload, at least now can not later version will have we do not know,