Forces EXPR to be interpreted in scalar context and returns the value of EXPR.
There is no equivalent operator to force an expression to
be interpolated in list context because in practice, this is never
needed. If you really wanted to do so, however, you could use
the construction @{[ (some expression) ]}
, but usually a simple
(some expression)
suffices.
Because scalar is a unary operator, if you accidentally use a parenthesized list for the EXPR, this behaves as a scalar comma expression, evaluating all but the last element in void context and returning the final element evaluated in scalar context. This is seldom what you want.
The following single statement:
is the moral equivalent of these two:
See perlop for more details on unary operators and the comma operator, and perldata for details on evaluating a hash in scalar contex.