Scalar and List context in Perl -

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1 @backwards = reverse qw(yabba dabba doo); 2 $backwards = reverse qw(yabba dabba doo); 3  4 print @backwards; #gives doodabbayabba 5 print $backwards."\n"; #gives oodabbadabbay 6 print @backwards."\n"; #gives 3

in above code why line 6 give 3 output? why convert scalar context if concatenated \n?

thanks

your question "why @backwards in scalar context in line 6", begs question, "how can determine term's context?".

context determined "what around" (i.e. "context") term.

how can determine term's context? looking @ operator/function using term.

what steps follow figure out context @backwards if didn't have helpful stackoverflow folks around tell context?

here have

print @backwards."\n"

so there 2 operators/functions. how know 1 provides context @backwards? consulting precedence. near top of perlop.pod have perl's precedence chart (print "list operator"):

left    terms , list operators (leftward) ... left    + - . ... nonassoc    list operators (rightward)

oh great, need know whether print leftward or rightward. consulting "terms , list operators (leftward)" section in perlop (right after precedence list) see print rightward here, because have not enclosed arguments in parenthesis.

so concatenation higher precedence, concatenation provides context @backwards.

next step check docs (perlop again) concatenation:

binary "." concatenates 2 strings.

strings scalars, binary "." concatenates 2 scalars.

and have it!

@backwards has scalar context because concatenation provides scalar context each of operands.

woo. easy, wasn't :-)


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