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5.14. Compare values - examples

Table 5-2. Compare values

Expression Value
"12.0" == 12 TRUE
"12.0" eq 12 FALSE
2 < 3 TRUE
2 lt 3 TRUE
12 > 3 TRUE
12 gt 3 FALSE !
"" == "hello" TRUE ! (Warning)
"" eq "hello" FALSE
"hello" == "world" TRUE ! (Warning)
"hello" eq "world" FALSE

When reading from STDIN you can always expect a string

Example 5-12. examples/scalars/is_empty_string.pl

#!/usr/bin/perl
use strict;
use warnings;

my $input = <STDIN>;
chomp $input;
if ($input == "") {     # wrong! use eq
    # empty string 
}
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