String comparison is always true [duplicate] - string

Question

This question already has answers here:
How do I compare two strings in Perl?
(7 answers)
Closed 1 year ago.
Here is the code that I currently have. Running on Perl v5.8.9.
#!/usr/bin/perl
# Prompts the user for their desired configuration
print "\n";
print "Please type BB for breadboard, or ACU for the Audio Control Unit.\n";
print "Do you want a BB or ACU version of alarm programmer: ";
$a = <STDIN>;
if($a == "ACU"){
print("Initiating alarm programmer for ACU...\n");
}else{
print("Initiating alarm programmer for breadboard...\n");
}
Here is some sample output:
C:\Users\U157280\Documents\Alarm Programmer>PerlAutonomy.pl
Please type BB for breadboard, or ACU for the Audio Control Unit.
Do you want a BB or ACU version of alarm programmer: ACU
Initiating alarm programmer for ACU...
And another one:
C:\Users\U157280\Documents\Alarm Programmer>PerlAutonomy.pl
Please type BB for breadboard, or ACU for the Audio Control Unit.
Do you want a BB or ACU version of alarm programmer: BB
Initiating alarm programmer for ACU...
As you can see, it selects ACU for both even though the statements appear to be correct.
What am I doing wrong?

Answer 1

Following code snippet is an OP's altered code with minimal corrections.
Please include into your scripts use strict; and use warnings, it will warn you about potential issues with your code -- in long run it will save you a lot of trouble with code correction.
You should use string comparison operator eq instead of number comparison operator ==
#!/usr/bin/perl
#
use strict;
use warnings;
use feature 'say';
# Prompts the user for their desired configuration
say '
Available options:
BB -- for breadboard
ACU -- for the Audio Control Unit
';
print ' Please make a choice: ';
my $choice = <>;
chomp($choice);
if( $choice eq 'ACU') {
say "\n Initiating alarm programmer for ACU...";
} elsif( $choice eq 'BB' ) {
say "\n Initiating alarm programmer for breadboard...";
} else {
say "\n Wrong choice...";
}
exit 0;
To run external command or script you should use system
Reference:
perlop
say
chomp
system

Answer 2

Try this:
#!/usr/bin/perl
# Prompts the user for their desired configuration
print "\n";
print "Please type BB for breadboard, or ACU for the Audio Control Unit.\n";
print "Do you want a BB or ACU version of alarm programmer: ";
$a = <STDIN>;
chomp($a);
if($a eq "ACU"){
print("Initiating alarm programmer for ACU...\n");
}else{
print("Initiating alarm programmer for breadboard...\n");
}
You had 2 issues, first, = is assignment not comparison. Second, you had a newline at the end of your input that you weren't accounting for. The chomp() gets rid of the newline, and the eq operator performs string comparison.