51 I guess the tag is a variable, and it is checking for 9eaf - but does this exist in Perl? What is the "=~" sign doing here and what are the "/" characters before and after 9eaf doing?
The => operator in perl is basically the same as comma. The only difference is that if there's an unquoted word on the left, it's treated like a quoted word. So you could have written Martin => 28 which would be the same as 'Martin', 28. You can make a hash from any even-length list, which is all you're doing in your example. Your Readonly example is taking advantage of Perl's flexibility with ...
Below are the flags that I encounter most often, and I don't have a clue what they mean: perl -pe perl -pi perl -p perl -w perl -d perl -i perl -t I will be very grateful if you tell me what each of those mean and some use cases for them, or at least tell me a way of finding out their meaning.
In Perl, what is a good way to perform a replacement on a string using a regular expression and store the value in a different variable, without changing the original? I usually just copy the string to a new variable then bind it to the s/// regex that does the replacement on the new string, but I was wondering if there is a better way to do this?
Output of perldoc -q round Does Perl have a round () function? What about ceil () and floor ()? Trig functions? Remember that int() merely truncates toward 0. For rounding to a certain number of digits, sprintf() or printf() is usually the easiest route.
Per perldoc perluniintro, Perl does not support using digits other than [0-9] as numbers, so I would definitely use [0-9] if the following are both true: You want to use the result as a number (such as performing mathematical operations on it or storing it somewhere that only accepts proper numbers (e.g. an INT column in a database)).
