well, can use eval: 
my $combined = join ' ', grep $_, map { my $value = eval "\$$_"; $valu
+e ? sprintf("%s=%s", $_, $value) :  undef } ( 'a' .. 'z' );

[download]
But comes with all the caveats of eval'ing arbitrary variables. I hope someone posted a way of doing this, which would make the map a lot simpler: 
  my $x = 3;
  print f($x);  # 'x'

[download]
Also note that it is bad to use $a and $b becaues it can/will cause confusion with the special variables used by sort.

In reply to Re: Scalar joining, concatenation, involving varying text by davidrw
in thread Scalar joining, concatenation, involving varying text by mhearse

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