Question

I am a perl noob still. I am getting a string which can be man_1, man_2, woman1, woman2 etc.. (no commas and there will be only one string as input to the function).

I need to check man_ or woman as substring in if statements to make sure appropriate number is extracted and some offset is added.

the number i can extract as below

$num =~ s/\D//g
if (<need the substring extracted> == "man_")
    $offset = 100;
else if (<need the substring extracted> == "woman")
    $offset = 10;

return $num + $offset;

Now how do I extract the substring. I looked at substr and it requires offsets and what not. Couldnt figure out. Appreciate the help

Answer 1

Solution:

if ( $num =~ m{^man_(\d+)$} ) {
    return 100 + $1;
} elsif ( $num =~ m{^woman(\d+)$} ) {
    return 10 + $1;
} else {
    die "Bad input: $num\n";
}

In your example there is couple of problems:

1. s/\D//g – will remove the characters, but one-by-one, and not as big block of all \D characters. So there is no variable that would be “man_”
2. to get data from regexp, you should use grouping parens, like s/(\D)//
3. to get all characters, you should use * or + operators, like: s/(\D+)//
4. Its still better to match without modifying, as it gives you better handling of edge cases of malformed data.