Re^2: resetting a foreach loop!

Your average specifically checks if no arguments are provided, but doesn't actually handle that situation. Fixed:

sub average {
    if (@_) {
        my $sum;
        for (@_) {
            $sum += $_;
        }
        return $sum/@_;
    } else {
        return undef;
    }
}
[download]

Same, but shorter:

sub sum { my $sum; $sum += $_ for @_; $sum }
sub avg { @_ ? sum(@_)/@_ : undef }
[download]

Comment on Re^2: resetting a foreach loop! Select or Download Code

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Re^3: resetting a foreach loop! by pryrt (Abbot) on Nov 17, 2017 at 19:36 UTC
++Indeed. Technically, the no-explicit-return version of the function returns 0 for an empty argument list, so it implictly handles the empty case. (I infer that the OP did the `if(@_)` just to prevent divide-by-zero.) But I agree that explicit undef is a better return value than relying on a default 0.	[reply] [d/l]
Re^4: resetting a foreach loop! by ikegami (Patriarch) on Nov 17, 2017 at 20:00 UTC
Technically, the no-explicit-return version of the function returns 0 for an empty argument list I am aware of that, but they are relying undefined behaviour to do so^[1], and it's a poor value to return. I infer that the OP did the if(@_) just to prevent divide-by-zero. That would actually have been a far better outcome! "If no `return` is found and if the last statement is an expression, its value is returned. If the last statement is a loop control structure like a foreach or a while , the returned value is unspecified. The empty sub returns the empty list."	[reply] [d/l]
Re^5: resetting a foreach loop! by AnomalousMonk (Archbishop) on Nov 17, 2017 at 20:15 UTC
"If no `return` is found [and] the last statement is a loop control structure like a foreach or a while , the returned value is unspecified. ..." Does this apply to `if`-blocks? I don't think of `if` as a "loop control" structure. Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]
Re^6: resetting a foreach loop! by ikegami (Patriarch) on Nov 18, 2017 at 00:07 UTC
Re^7: resetting a foreach loop! by AnomalousMonk (Archbishop) on Nov 18, 2017 at 00:43 UTC
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