> print " { +map [1, 2, 3, $_], (4) }" # prints
nothing
In scalar context map returns the number of elements
generated.
{
... } is a scalar context, expecting some sort of
reference.
Here, map returns 1 in scalar context, and print prints .
% perl -lwe 'print "{ +map [1, 2, 3, $_], (4)
}"'
% perl -Mstrict -lwe 'print "{ +map [1, 2, 3, $_], (4)
}"'
Can't use string ("1") as an ARRAY ref while
"strict refs" in use at -e line 1
% perl -lwe '1 = qw(Hello world); print "{ +map
[1, 2, 3, $_], (4) }"'
Helloworld
However, this works:
% perl -lwe 'print "{ (map [1, 2, 3, $_],
(4))[0] }"'
1234
Robin
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