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What's the difference between my ($variableName) and my $variableName in Perl?

What's the difference between my ($variableName) and my $variableName in Perl? What to the parentheses do?

Solution

  • The important effect is when you initialize the variable at the same time that you declare it:

    my ($a) = @b;   # assigns  $a = $b[0]
my $a = @b;     # assigns  $a = scalar @b (length of @b)

    The other time it is important is when you declare multiple variables.

    my ($a,$b,$c);  # correct, all variables are lexically scoped now
my $a,$b,$c;    # $a is now lexically scoped, but $b and $c are not

    The last statement will give you an error if you use strict.