Wikipedia:Reference desk/How to ask a software question

The question

When asking for help with software, users often ask questions which nobody could possibly answer. Here is an example:

I am writing a Perl program, but it doesn't work. I am reading in the names but they come out wrong. Is there a solution?

The question is unanswerable for three reasons:

1. readers don't know what the goal is
2. readers don't know what the problem is
3. readers don't have example source code in which to look for the problem

I want to make a epaper website like epaper.indianexpress.com, can anybody help me?technologies is not bar, currently i m planning in PHP

Problem

That's better, but there's still no way for readers to answer the question -- they still don't know what the problem is! You must describe what's going wrong.

Let's fix the request so that the problem is stated:

I am writing a Perl program, but it doesn't work. The program should read in a list of names, and then print them in alphabetical order. I am reading in the names but they come out in the wrong order. In fact, they come out in same order that they started in! Is there a solution?

I want to make a epaper website like epaper.indianexpress.com, can anybody help me?technologies is not bar, currently i m planning in PHP

Finally, an answer!

Here's a good answer to the question, which would not have been possible when we started:

The problem is on line 10. Unlike the sort() function in some languages, Perl's sort() does not re-order the list "in-place". It actually makes a copy of the list and then sorts and returns that. Changing line 10 to:

   @people = sort @people;

will fix the problem. This is actually a pretty common mistake, and perl will catch it for you if you turn "warnings" on. To do that, change the first line to:

   #!/usr/bin/perl -w

and perl will say:

Useless use of sort in void context at line 10.

which is a little obscure, but at least tells you to look for trouble on that line. Using -Mdiagnostics instead will give you a very long and helpful explanation. -- PerlyGates 22:39, 18 August 2009 (UTC)

External links

• How To Ask Questions The Smart Way - A thorough but long-winded treatise on asking technical questions.
• How do I post a question about code that doesn't work correctly? A C++-oriented checklist for posting good questions.