Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Function pointer equivalent

Posted on 2008-06-20
3
Medium Priority
?
770 Views
Last Modified: 2012-06-27
Hi,

I'm trying to figure out this perl syntax for passing a function 'pointer'.

    sub test (&@)
    {
        my ($function, @data) = @_;
    }

so do the two egyptian hieroglyphs mean that the sub only takes a sub, then an array as parameters? How exactly do I pass a sub to a call of test(), like:

    sub saysomething()
    {
         print("hello\n");
    }

    test(saysomething, @myarray);


If that's right, how can I then call $function once it's passed to test, and even pass a parameter to it?

Thanks
0
Comment
Question by:DJ_AM_Juicebox
3 Comments
 
LVL 85

Accepted Solution

by:
ozo earned 2000 total points
ID: 21830301
sub test (&@)
    {
        my ($function, @data) = @_;
        &$function(@data);
    }
  sub saysomething
    {
         print("hello @_\n");
    }


test(\&saysomething, "my","array");
0
 

Author Comment

by:DJ_AM_Juicebox
ID: 21830877
Why do you have the:

    \&

before saysomething, I left it out and it still seems to work ok - what is the effect?

Thanks
0
 
LVL 39

Expert Comment

by:Adam314
ID: 21831138
The \& returns a reference to the subroutine.  If you have the use strict and use warnings options turned on, it will not work without the \&.
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

On Microsoft Windows, if  when you click or type the name of a .pl file, you get an error "is not recognized as an internal or external command, operable program or batch file", then this means you do not have the .pl file extension associated with …
In the distant past (last year) I hacked together a little toy that would allow a couple of Manager types to query, preview, and extract data from a number of MongoDB instances, to their tool of choice: Excel (http://dilbert.com/strips/comic/2007-08…
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…
Six Sigma Control Plans

927 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question