 laziness, impatience, and hubris PerlMonks

### Re^4: How do I quickly strip blank space from the beginning/end of a string?

by blahblahblah (Priest)
 on Jul 22, 2009 at 01:12 UTC ( #782138=note: print w/replies, xml ) Need Help??

Good point. I've tried the 3 methods below:
```if (\$x =~ /\s/)
[download]```
and
```if (substr(\$x, -1) =~ /^\s/
[download]```
and
```if (rindex(\$x," ") == 0 || rindex(\$x,"\r") == 0 ||  rindex(\$x,"\n") ==
+ 0 ||  rindex(\$x,"\t") == 0)
[download]```
The rindex method is much faster on the data that has spaces; otherwise the substr method is the fastest. Any other good ideas, keeping in mind that the data (I think) won't often contain any trailing spaces?

Replies are listed 'Best First'.
Re^5: How do I quickly strip blank space from the beginning/end of a string?
by ikegami (Pope) on Jul 22, 2009 at 04:22 UTC

\$x =~ /\s/
doesn't work. It should be
\$x =~ /\s\z/
Bonus: The speed of fixed version won't depend on the length of the string like the broken one did.

if (rindex(\$x," ") == 0 || rindex(\$x,"\r") == 0 || rindex(\$x,"\n") == 0 || rindex(\$x,"\t") == 0)
doesn't work. It should be
if (rindex(\$x," ") == length(\$x)-1 || rindex(\$x,"\n") == length(\$x)-1 || rindex(\$x,"\t") == length(\$x)-1 || rindex(\$x,"\r") == length(\$x)-1)
Or just
my \$ch = substr(\$x, -1); \$ch eq " " || \$ch eq "\n" || \$ch eq "\t" || \$ch eq "\r"

And then there's
length(\$x) && index(" \n\t\r", substr(\$x, -1)) >= 0

You should be concentrating on writing code that actually works before worrying about operations that take 0.00001 second.

Log In?
 Username: Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://782138]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others making s'mores by the fire in the courtyard of the Monastery: (4)
As of 2019-05-21 02:56 GMT
Sections?
Information?
Find Nodes?
Leftovers?
Voting Booth?
Do you enjoy 3D movies?

Results (129 votes). Check out past polls.

Notices?