Re^2: appending a variable

Yes, braces are one way to disambiguate where the variable name ends.
Often I will use the concatenate operator to avoid the need for braces.
This probably runs slower, but you can space out the var names to be substituted in order to make them more obvious (YMMV).

my $opstr = '01';
my $foo = "a_${opstr}_b";
my $bar = 'a_'. $opstr .'_b';

print "$foo\n";
print "$bar\n";
[download]

Also, OP probably meant: my ($opstr) = $vmstr =~ /-(\d+)$/; in the case of one digit (e.g. 0)?

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Re^3: appending a variable by Fletch (Bishop) on Apr 28, 2022 at 20:24 UTC
Aktchually they compile down to the same thing under the hood (because the former is just syntactic sugar for the latter more or less): `$ perl -MO=Deparse,-p,-q -E 'my $foo = qq{a_${blah}_b}; my $bar = q{a_ +} . $blah . q{_b};' use feature 'current_sub', 'bitwise', 'evalbytes', 'fc', 'postderef_qq +', 'say', 'state', 'switch', 'unicode_strings', 'unicode_eval'; (my $foo = 'a_' . $blah . '_b'); (my $bar = 'a_' . $blah . '_b'); -e syntax OK` [download] The cake is a lie. The cake is a lie. The cake is a lie.	[reply] [d/l]
Re^4: appending a variable by pragovnj (Acolyte) on Apr 28, 2022 at 21:13 UTC
Hi, I got an error "Can't call method "YYYYmmddHHMMSS" on an undefined value" at $FN_OUTPUT This is my code `my $vmstr = "zldcdyh1bdce2d14-xxx-vccpohr-correlator-0"; my ($opstr) = $vmstr =~ /-(\d\d)$/; #using the value of $vmstr + of the VM but with an added 0 my $OPinst = "/PMOSS_SIPNBVQM_5MIN_OHDR_${YYYYmmddHHMMSS$opstr}"; my $P3inst = "/PMOSS_P3_SIPNBVQM_5MIN_OHDR_${YYYYmmddHHMMSS$opstr +}"; $FN_OUTPUT = "$DST_DIR${OPinst}_${INSTANCE}_$$"; # Suff +ixes added later: .processing .completed $FN_P3_OUTPUT ="$DST_DIR${P3inst}_${INSTANCE}_$$"; # Suf +fixes added later: .processing .completed` [download] Is this incorrect	[reply] [d/l]
Re^5: appending a variable by hippo (Archbishop) on Apr 28, 2022 at 21:35 UTC
Yes, it is incorrect. You now have a $ inside braces - why have you done that? Fixing these 8 lines in isolation gives: `my $vmstr = "zldcdyh1bdce2d14-xxx-vccpohr-correlator-0"; my ($opstr) = $vmstr =~ /-(\d\d)$/; #using the value of $vmstr + of the VM but with an added 0 my $OPinst = "/PMOSS_SIPNBVQM_5MIN_OHDR_$YYYYmmddHHMMSS$opstr"; my $P3inst = "/PMOSS_P3_SIPNBVQM_5MIN_OHDR_$YYYYmmddHHMMSS$opstr" +; $FN_OUTPUT = "$DST_DIR${OPinst}_${INSTANCE}_$$"; # Suff +ixes added later: .processing .completed $FN_P3_OUTPUT ="$DST_DIR${P3inst}_${INSTANCE}_$$"; # Suf +fixes added later: .processing .completed` [download] Note however that $INSTANCE is undefined. It is always best to provide an SSCCE. 🦛	[reply] [d/l]
Re^6: appending a variable by pragovnj (Acolyte) on Apr 28, 2022 at 22:26 UTC
Re^7: appending a variable by GrandFather (Saint) on Apr 28, 2022 at 23:36 UTC
Re^7: appending a variable by Marshall (Canon) on Apr 29, 2022 at 01:28 UTC
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