in reply to Re: Idiomatic Perl?
in thread Idiomatic Perl?

Is it okay to just do my $str = chomp(<STDIN>);?

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Re^3: Idiomatic Perl?
by haukex (Archbishop) on Mar 20, 2018 at 14:46 UTC
    Is it okay to just do my $str = chomp(<STDIN>);?

    No, because chomp is a bit special: it modifies its argument(s) and returns the total number of characters removed from all its arguments. The code you showed would fail because chomp wants to modify its arguments, but can't modify <STDIN> itself.

    The reason chomp( my $str = <STDIN> ); works is because a scalar assignment in Perl like ( my $str = <STDIN> ) is modifiable (an "lvalue"), as described in Assignment Operators: "Modifying an assignment is equivalent to doing the assignment and then modifying the variable that was assigned to."

    If you want to be a little bit more verbose, what you can do is:

    my $str = <STDIN>; chomp($str);
      Extra parens arent idiomatic :p  chomp $foo;
Re^3: Idiomatic Perl?
by 1nickt (Canon) on Mar 20, 2018 at 14:30 UTC

    Try it! What does it return?

    If it's not what you want, another approach might be to call the chomp on the result of the assignment:

    chomp( my $str = <STDIN> );

    Hope this helps!


    The way forward always starts with a minimal test.
Re^3: Idiomatic Perl?
by Corion (Patriarch) on Mar 20, 2018 at 14:47 UTC

    Depends on what you want to have in $str. Read chomp to learn about the return value of chomp.

      perl -we 'chomp <>'

      > Can't modify <HANDLE> in chomp at -e line 1, at EOF

      ($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord }map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,