PHP uses the func_get_args and func_num_args functions to implement function overload instances.

This article mainly introduces how PHP uses func_get_args and func_num_args functions to implement function overloading. The example shows the specific methods for PHP to implement overload, which is a very practical technique. For more information, see

This article mainly introduces how PHP uses func_get_args and func_num_args functions to implement function overloading. The example shows the specific methods for PHP to implement overload, which is a very practical technique. For more information, see

This example describes how PHP uses the func_get_args and func_num_args functions to implement function overloading. Share it with you for your reference. The specific method is analyzed as follows:

Friends who learn php know that php itself has no function overload, not to mention how to use it like java and c ,, however, if you have a deep understanding of the function, you can use the func_get_args () and func_num_args () functions in php to implement function overloading. The following are two examples of function overloading. these two functions implement function overloading.

1. default parameter. If a function is not a required parameter and the corresponding default value is added, the corresponding function can be completed. The Code is as follows:

The Code is as follows:

Function overloadFun ($ param1, $ param2 = '1', $ param3 = true)
{
// Do something
}

Use the func_get_args () and call_user_func_array () functions. The PHP code is as follows:

The Code is as follows:

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 ($ arg1, $ arg2 ){
Echo $ arg1, '', $ arg2;
}

Rewrite ('php'); // call func1
Rewrite ('php', 'China'); // call func2

2. Use the default value to obtain the desired result based on the input. The Code is as follows:

The Code is as follows:

Function test ($ name = "Xiao Li", $ age = "23 "){
Echo $ name. "". $ age;
}
Test ();
Echo"
";
Test ("");
Echo"
";
Test ("a", "B ");

3. Use the _ call ($ name, $ arg) function for processing. The Code is as follows:

The Code is as follows:

<? Php
Class OverLoad {
Function _ call ($ name, $ args)
{
If ($ name = 'overloadfun ')
{
Switch (count ($ args ))
{
Case 0: $ this-> overloadFun0 (); break;
Case 1: $ this-> overloadFun1 ($ args [0]); break;
Case 2: $ this-> overloadFun2 ($ args [0], $ args [1]); break;
Default: // do something
Break;
}
}
}

Function overloadFun0 ()
{
Echo 0;
}

Function overloadFun1 ($ var1)
{
Echo $ var1;
}

Function overloadFun2 ($ var1, $ var2)
{

Echo $ var1 + $ var2;
}
}
$ Test = new OverLoad ();
$ Test-> overloadFun ()."
".
$ Test-> overloadFun (1 )."
".
$ Test-> overloadFun (1, 2 )."
";
?>

With this method, we can use them to implement simple function overloading, but one thing to note is that php, as a weak type language, cannot be like a strong type such as java, c ++ directly implements heavy load, at least not now. We don't know if it will be available in later versions.

I hope this article will help you with PHP programming.