Beefy Boxes and Bandwidth Generously Provided by pair Networks
Welcome to the Monastery
 
PerlMonks  

perlfunc:reverse

by gods
on Aug 24, 1999 at 22:42 UTC ( #244=perlfunc: print w/ replies, xml ) Need Help??

reverse

See the current Perl documentation for reverse.

Here is our local, out-dated (pre-5.6) version:


reverse - flip a string or a list



reverse LIST



In list context, returns a list value consisting of the elements of LIST in the opposite order. In scalar context, concatenates the elements of LIST, and returns a string value consisting of those bytes, but in the opposite order.

    print reverse <>;           # line tac, last line first

    undef $/;                   # for efficiency of <>
    print scalar reverse <>;    # byte tac, last line tsrif

This operator is also handy for inverting a hash, although there are some caveats. If a value is duplicated in the original hash, only one of those can be represented as a key in the inverted hash. Also, this has to unwind one hash and build a whole new one, which may take some time on a large hash.

    %by_name = reverse %by_address;     # Invert the hash

Log In?
Username:
Password:

What's my password?
Create A New User
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others avoiding work at the Monastery: (5)
As of 2015-07-07 04:33 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









    Results (87 votes), past polls