DIFFERENCE BETWEEN VARIABLE

iguane has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: DIFFERENCE BETWEEN VARIABLE by ChOas (Curate) on Jan 31, 2001 at 15:18 UTC
I can tell you that you should use: strict -w $output when using strict, and -w ${'output'} results in: Can't use string ("output") as a SCALAR ref while "strict refs" in use at ./lal line 8. When you use ${'output'} you are trying to dereference 'output'... To be more exact: using $output means using whatever output contains. using ${'output'} means using whatever 'output' points to, since it is highly unlikely that 'output' is/will ever become a valid reference, this results in an error (caught by 'use strict') GreetZ!, ChOas print "profeth still\n" if /bird\|devil/;	[reply]
Re: DIFFERENCE BETWEEN VARIABLE by autark (Friar) on Jan 31, 2001 at 18:36 UTC
Actually, there is a difference between `$output` and `${'output'}`: `$output = "global"; { my $output = "my"; print $output; print ${'output'}; }` [download] This little example will first print out "my" then "global". This is because the latter is a symbolic reference to the `$output` variable - hence it will always refer to the global variable (which is stored in the package stash). `${output}` on the other hand is not a symbolic reference, and will still refer to the lexical variable (if one exists). Autark.	[reply] [d/l] [select]
Re: DIFFERENCE BETWEEN VARIABLE by quidity (Pilgrim) on Jan 31, 2001 at 17:20 UTC
There is no difference, as far as perl is concerned, this is often a useful construct (albeit without the `' '` characters) which allows variables to be interpolated in strings next to other `[A-Za-z_]` characters: `$varname = 'poke'; print "${varname}mon\n";` [download] Will output: `pokemon` while you could not have said: `print "$varnamemon\n";` as there is no such variable. You could avoid this by using `.` instead, but you'll see instances of the construct above.	[reply] [d/l] [select]


laziness, impatience, and hubris
	PerlMonks