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Re: Question about concatenation

by eyepopslikeamosquito (Chancellor)
on Dec 23, 2012 at 20:27 UTC ( #1010120=note: print w/replies, xml ) Need Help??


in reply to Question about concatenation

The difference is because the range operator behaves differently in list context to scalar context. BTW, so do arrays. As indicated in the test program below, the array returns the number of elements in scalar context, while the flip flop operator returns false (represented as undef), which prints as an empty string. Running:

use strict; use warnings; print "Counting up: " . (1..6) . "\n"; # scalar context (undef) print "Counting up: " , (1..6) , "\n"; # list context print "Counting up: @{[1..6]}\n"; # list context, space bet +ween each element my @one_to_six = 1..6; print "Counting up: " . @one_to_six . "\n"; # scalar context (no. of +elts) print "Counting up: " , @one_to_six , "\n"; # list context
produces:
Use of uninitialized value $. in range (or flip) at cnt.pl line 4. Counting up: Counting up: 123456 Counting up: 1 2 3 4 5 6 Counting up: 6 Counting up: 123456

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