Perl array vs list

Question

I have two data structures in Perl:

An array:

my @array2 = ( \"1\", \"2\", \"3\");

for $elem (@array2) {
    print $elem.\"\\n\";
}

<

Answer 1

The square brackets are used to create an anonymous array. When evaluated, it returns a reference to this array, not the actual array values.

Parentheses have no such hidden property, but simply override precedence inside expressions, much like in math. For example:

my @array = 1,2,3;

Is actually evaluated like this:

my @array = 1;
2,3; # causes the warning "Useless use of constant in void context"

because the = operator has higher precedence than the commas. So to get around that, we use parentheses when assigning arrays, like so:

my @array = (1,2,3);

Your example:

my @array = [1,2,3];

is somewhat like saying this:

my @tmp = (1,2,3);
my @array = \@tmp;

Where the \ is used to create a reference to the @tmp array.