Beefy Boxes and Bandwidth Generously Provided by pair Networks
Just another Perl shrine

Re: Check even numbers?

by cees (Curate)
on Aug 07, 2006 at 05:02 UTC ( #565891=note: print w/replies, xml ) Need Help??

in reply to Check even numbers?

If you want to count the number of occurences of a single character in a string, then you should look at using 'tr'.

$str = 'ABABAABBA'; $count = $str =~ tr/A//; # $a = 5;

If you omit the second arg to tr, it knows you are not changing the string, but still counts up the occurences for you, which makes this very efficient.

After that you just have to see if the number is positive ($count > 0) and use Grandfather's test above to see if it is even ( !($count & 1) ).

if ($count && !($count & 1)) { # Do something with this protein sequence }

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://565891]
[marto]: #deletefacebook
[LanX]: well try to find my profile xD
[marto]: derp
[marto]: I've never had an account, and wouldn't visit the site
LanX having only a fake profile is hard if a flirt asks to befriend you
[erix]: "surveillance companies" have been rebranded as "social media"
[LanX]: I'm using whatapp though :-/
[LanX]: Snowden remins me of Evan Spiegel (... start of a new conspiracy theory)
[LanX]: yes! The same person!

How do I use this? | Other CB clients
Other Users?
Others about the Monastery: (4)
As of 2018-03-19 15:27 GMT
Find Nodes?
    Voting Booth?
    When I think of a mole I think of:

    Results (240 votes). Check out past polls.