see perlglossary

I see. But I want to know why in my ($x, $y, $z) = qw( 1 2 3 ); it's returning the lvalues in list context and why in ( $x, $y, $z ) = qw( a b c ); it's returning nothing?

And in the expression (my ($x, $y, $z) = qw( 1 2 3 )) = qw( a b c ); it's returning nothing as well?

c:\@Work\Perl\monks>perl -wMstrict -le
"my ($x, $y, $z);
 ;;
 ($x, $y, $z) = qw( 1 2 3 );
 print qq{$x, $y, $z};
 ;;
 (($x, $y, $z) = qw( 1 2 3 )) = qw( a b c );
 print qq{$x, $y, $z};
 ;;
 ((($x, $y, $z) = qw( 1 2 3 )) = qw( a b c )) = qw(foo bar baz);
 print qq{$x, $y, $z};
"
1, 2, 3
a, b, c
foo, bar, baz
[download]

The expression  ($x, $y, $z) = ... evaluates to a list of assignable values, i.e., lvalues.
The expression  ($x, $y, $z) = RHS evaluates to the list of assignable values, i.e., lvalues, $x, $y, $z.

And likewise with

c:\@Work\Perl\monks>perl -wMstrict -le
"my ($x, $y, $z) = qw( 1 2 3 );
 print qq{$x, $y, $z};
 ;;
 (my ($u, $v, $w) = qw( 1 2 3 )) = qw( a b c );
 print qq{$u, $v, $w};
 ;;
 ((my ($r, $s, $t) = qw( 1 2 3 )) = qw( a b c )) = qw(foo bar baz);
 print qq{$r, $s, $t};
"
1, 2, 3
a, b, c
foo, bar, baz
[download]

---

Give a man a fish:  <%-{-{-{-<

• context

  The surroundings or environment. The context given by the surrounding code determines what kind of data a particular expression is expected to return.

• void context

  A form of scalar context in which an expression is not expected to return any value at all and is evaluated for its side effects alone.

• side effects

  Something extra that happens when you evaluate an expression. Nowadays it can refer to almost anything. For example, evaluating a simple assignment statement typically has the “side effect” of assigning a value to a variable. ...

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}