multiple if-else statement confusion perl - perl

Question

I'm having a problem with my if-else statement. Even if the $key I'm using matches the text in my if statement, the else statement I have at the bottom is also evaluated, so I'm getting multiple values for each $key, which is a problem. What am I doing wrong here?
my $key = $line[0];
if ($key eq 'this_setting') {
my $counter1 = $counter + 1;
my $counter2 = $counter + 2;
$value = join(' ', #line[$counter1..$counter2]);
$my_setting_hash{$key} = $value;
}
if ($key eq 'some_setting_abc') {
my $counter1 = $counter + 1;
my $counter2 = $counter + 2;
$value = join(' ', #line[$counter1..$counter2]);
$my_setting_hash{$key} = $value;
}
if ($key eq 'another_setting_123') {
my $counter1 = $counter + 1;
my $counter3 = $counter + 3;
$value = join(' ', #line[$counter1..$counter3]);
$my_setting_hash{$key} = $value;
}
else {
my $counter1 = $counter + 1;
$value = $line[$counter1];
$my_setting_hash{$key} = $value;
}
Why is this else statement not bypassed if one of my if statements is evaluated?

Answer 1

You need to chain them together with elsif:
my $key = $line[0];
if ($key eq 'this_setting') {
my $counter1 = $counter + 1;
my $counter2 = $counter + 2;
$value = join(' ', #line[$counter1..$counter2]);
$my_setting_hash{$key} = $value;
}
elsif ($key eq 'some_setting_abc') {
my $counter1 = $counter + 1;
my $counter2 = $counter + 2;
$value = join(' ', #line[$counter1..$counter2]);
$my_setting_hash{$key} = $value;
}
elsif ($key eq 'another_setting_123') {
my $counter1 = $counter + 1;
my $counter3 = $counter + 3;
$value = join(' ', #line[$counter1..$counter3]);
$my_setting_hash{$key} = $value;
}
else {
my $counter1 = $counter + 1;
$value = $line[$counter1];
$my_setting_hash{$key} = $value;
}
Otherwise, the first two if statements are independent of the third if/else statement.

Answer 2

As has already been pointed out, you need the keyword elsif
However, another solution is to put your special rules for each key into a hash and so that you can share code:
my %key_length = (
this_setting => 1,
some_setting_abc => 1,
another_setting_123 => 2,
);
my $key = $line[0];
my $index_low = $counter + 1;
my $index_high = $index_low + ($key_length{$key} // 0);
$my_setting_hash{$key} = join ' ', #line[ $index_low .. $index_high ];

Answer 3

Let's say $key's value is 'some_setting_abc'. Your first if does not apply, but the second if does. The third if does not apply either but that one has an else therefore that is executed. As #TedHopp pointed out, you need a single if with chained elsifs and a final else instead.
However, I want to point out that there is a lot of duplication in your code. Life is simpler when you write code a bit more succinctly:
my $key = $line[0];
my $index = $counter + 1;
if (($key eq 'this_setting') or ($key eq 'some_setting_abc')) {
$my_setting_hash{$key} = join ' ', #line[$index .. ($index + 1)];
}
elsif ($key eq 'another_setting_123') {
$my_setting_hash{$key} = join ' ', #line[$index .. ($index + 2)];
}
else {
$my_setting_hash{$key} = $line[$index];
}