Re^3: scope of variables in a sub


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Re^3: scope of variables in a sub

by tobyink (Canon)

on Sep 24, 2020 at 10:29 UTC ( [id://11122155]=note: print w/replies, xml )

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in thread scope of variables in a sub

Assignment in an if is fine if you're doing:

if ( my $var = something() ) {
  # use $var here
}
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(Ditto while.)

But if $var has a wider scope, it's probably a bad idea.

toby döt ink

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Re^4: scope of variables in a sub
by GrandFather (Saint) on Sep 24, 2020 at 21:04 UTC

Even then there are two major issues to my mind:

The clutter around the assignment hides the assignment making it harder to see where the variable gets its value
It is easy to confuse = and == so using the assignment operator in a conditional expression makes code harder to maintain

Point 2 is seen as sufficient of an issue that many compilers generate warnings for assignment in conditional expressions. I love the way that Perl allows terse functional chords that allow the equivalent of many lines of code in other languages to be wrapped up in a single compact statement. But playing tricks with side effects just to save a line of code doesn't sit well with me.

I'm completely fine with the equivalent assignment in a while statement though - go figure.

Optimising for fewest key strokes only makes sense transmitting to Pluto or beyond

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