Beefy Boxes and Bandwidth Generously Provided by pair Networks
Clear questions and runnable code
get the best and fastest answer

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
Didn't we do a debugging thread here a while back? Might be worth it to check.

In any event, I think the most important thing I learned in my 28 years of programming is "debugging is hard". So I spend nearly every moment of my time while I'm programming thinking about how not to put bugs in in the first place, or at least have a pretty good idea what I just broke on the last edit cycle.

My methodology is basically:

  1. Start with an empty file.
  2. Write a dozen lines of code
  3. Run it
  4. If that doesn't work, add a few warn statements until I see what I broke, and fix it.
  5. Add another dozen lines of code. Repeat.
The key seems to be small incremental progress. Note that this methodology works for command-line, CGI, and whatever. Always have a testable version that's no more than a dozen lines different from the one you're working on. Then you'll know your error is always within the last dozen lines of code you wrote.

Another element is "understand what you type". You should be able to have a complete mental model of every step of what you type. Yeah, it sounds so basic, but I'm amazed when I watch my students copy random lines of code into their program and then say "it didn't work". When I ask them what a particular line does, they say "I don't know". Gosh, how do they expect it to work then!?

So maybe the combined rule is "never type faster than you can understand". {grin}

-- Randal L. Schwartz, Perl hacker

In reply to Re: Are debugging skills atrophying? by merlyn
in thread Are debugging skills atrophying? by dws

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others wandering the Monastery: (7)
    As of 2015-11-30 08:08 GMT
    Find Nodes?
      Voting Booth?

      What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

      Results (765 votes), past polls