Re^2: Passing Variables

sub find_average needs to:

initialize my $sum = 0;
handle the arg list being empty. You probably don't want to throw a divide-by-zero exception.

I suppose I'd write sub above_average like this:

   sub above_average  
   {
       my $average_num = shift;
       grep { $_ > $average_num } @_
    }
[download]

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Re^3: Passing Variables by Marshall (Canon) on Feb 25, 2021 at 23:38 UTC
Your comments are appropriate, thanks! My goal was to refactor the OP's code in a straight-forward way, with the intent of being instructive - there are of course imperfections . When coding this myself, I would be thinking about functions in List::Util and passing references to array instead of an array itself. But that is not what I thought my job here was. My intent was to present easy to understand code. But even so, I figure that the OP will have some questions about it.	[reply]
Re^4: Passing Variables by GrandFather (Saint) on Feb 28, 2021 at 23:29 UTC
Example code that skips error handling, unless that is made clear in the accompanying text, is an example of how to do something badly. I'm sure you didn't intend it like that, but error handling and considering edge cases are the key to writing robust reliable code. Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply]
Re^5: Passing Variables by Marshall (Canon) on Mar 13, 2021 at 19:41 UTC
Well, jdporter says: "handle the arg list being empty. You probably don't want to throw a divide-by-zero exception." I am actually fine with that error code! I have written Perl code that intercepts various warnings in situations where I can actually fix the problem. I remember one sort routine where a numeric comparison didn't work and the code defaulted back to an alpha comparison. There is no "fix" for a "divide by zero". I added comments about this in further code. Grandfather is right about that. Document limitations. In the code, allowing Perl to throw a "divide by zero" exception is fine. The code is short. Detecting and printing an error that "will happen" is unnecessary, because there is no "fix" for that error.	[reply]
Re^6: Passing Variables by GrandFather (Saint) on Mar 14, 2021 at 20:04 UTC
Re^3: Passing Variables by GrandFather (Saint) on Mar 01, 2021 at 00:40 UTC
"initialize my $sum = 0;" An interesting variation, that is probably premature optimization in simple cases, is to: `sub average { my $sum = shift @_; ...;` [download] For algorithms such as moving averages or integrators initializing the accumulator with the first sample value can be essential to avoiding large glitches at the start of the result data. Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond	[reply] [d/l]


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