Another way to pass a parameter, count

Func_num_args Function Function – returns the number of arguments passed to the function, with the following syntax:

int Func_num_args (void).

Description: Returns the number of arguments passed to the currently defined function. If you call this function from outside the function definition, func_get_arg () will produce a warning.

Func_num_args () can be used to combine Func_get_arg () and Func_get_args () to allow a user-defined function to accept the Variable-length parameter list.

Func_get_arg () returns the item from the argument list with the syntax: int func_get_arg (int arg_num), returning the Arg_num parameter of the parameter list that defines the function, whose arguments start with 0. and calling this function outside the function definition generates a warning, and when Arg_num is greater than the number of arguments actually passed by the function, it also generates a warning and returns false.

The difference between the Func_get_args () function and the Func_get_arg () function is that the Func_get_args () function returns an array whose elements correspond to the number of parameter columns of the current consumer-defined function. When we build PHP classes, flexible use of these three functions, can play a very good effect, such as outside in the creation of PHP and MySQL link class, you can write the following code:

[PHP]View Plaincopyprint?

1. <pre name= "code"  class= "php" ><?phpclass  Mydb{private  $user; $pass; $host; $db; function __construct () { $num _args=func_num_args (); span class= "keyword" >if ( $num _args>0) { $args =func_get_args (); $this->host= $args [0]; $this->user= $args [1]; $this->pass= $args [2];this->connect ();}} ............ Omitted............? ></pre><br>  
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Another way to pass a parameter, count