Some PHP functions and functions that you don't know before

The real power of PHP comes from its functions, but some PHP functions are not fully utilized, and not everyone will read the manual and function reference page by page from start to end, here we will introduce you to these practical functions and functions. 1. functions with any number of parameters you may already know. PHP allows defining functions with optional parameters. But there are also fully permitted "> <LINKhref =" http://www.php100.co

The real power of PHP comes from its functions, but some PHP functions are not fully utilized, and not everyone will read the manual and function reference page by page from start to end, here we will introduce you to these practical functions and functions.

1. functions with any number of parameters

You may already know that PHP allows defining functions with optional parameters. However, there are methods that fully allow any number of function parameters. The following is an example of an optional parameter:

1. Reference content is as follows:
2.  
3. // Functionwith2optionalarguments
4. Functionfoo ($ arg1 = ", $ arg2 = "){
5.  
6. Echo "arg1: $ arg1 \ n ";
7. Echo "arg2: $ arg2 \ n ";
8.  
9. }
10.  
11. Foo ('hello', 'World ');
12. /* Prints:
13. Arg1: hello
14. Arg2: world
15. */
16.  
17. Foo ();
18. /* Prints:
19. Arg1:
20. Arg2:
21. */

Now let's see how to create a function that can accept any number of parameters. This time, you need to use the func_get_args () function:

1. Reference content is as follows:
2.  
3. // Yes, theargumentlistcanbeempty
4. Functionfoo (){
5.  
6. // Returnsanarrayofallpassedarguments
7. $ Args = func_get_args ();
8.  
9. Foreach ($ argsas $ k =>$ V ){
10. Echo "arg". ($ k + 1). ": $ v \ n ";
11. }
12.  
13. }
14.  
15. Foo ();
16. /* Printsnothing */
17.  
18. Foo ('Hello ');
19. /* Prints
20. Arg1: hello
21. */
22.  
23. Foo ('hello', 'World', 'Again ');
24. /* Prints
25. Arg1: hello
26. Arg2: world
27. Arg3: again
28. */