Simple Java Trim Help - Overclock.net

LyokoHaCk · 04-17-08

I can't find a way to trim the last character of a StringBuilder or a String for that matter. How can I do it? The is no trimEnd(...) and trim doesn't accept arguments.
TY

Scriptorum · 04-18-08

Once you go regular expressions you never go back!

Code:

str = str.replaceAll(" +$", "");

That replaces all spaces at the string end, if any are there. To just replace a single space at the end (if any), use the pattern:

Code:

" $"

or to trim the last character, regardless of what it is, use:

Code:

".$"

rabidgnome229 · 04-18-08

If you have a String called 's'

Code:

s.substring(0, s.length()-1);

If you have a StringBuilder 'sb'

Code:

sb.deleteCharAt(sb.length()-1);

Quote:

Originally Posted by Scriptorum

Once you go regular expressions you never go back!

Code:

str = str.replaceAll(" +$", "");

That replaces all spaces at the string end, if any are there. To just replace a single space at the end (if any), use the pattern:

Code:

" $"

or to trim the last character, regardless of what it is, use:

Code:

".$"

This won't actually shorten the string will it? Plus, regexps would almost certainly be slower

Scriptorum · 04-18-08

Quote:

Originally Posted by rabidgnome229

This won't actually shorten the string will it? Plus, regexps would almost certainly be slower

It will shorten the string; replaceAll and replaceFirst replace the matched pattern with the supplied second parameter, and they return the modified string. I agree that regex is slower than a simple substring, but the difference is negligible unless you're doing thousands of string replacements in a tight loop. Your substring example is good if what the OP wants is to blindly remove the last character, but / +$/ is safer for trimming because it will chop more than one space and it will not chop if there are no spaces at the end to trim.

rabidgnome229 · 04-18-08

Quote:

Originally Posted by Scriptorum

It will shorten the string; replaceAll and replaceFirst replace the matched pattern with the supplied second parameter, and they return the modified string.

I see - I've never used regexp in java

Quote:

I agree that regex is slower than a simple substring, but the difference is negligible unless you're doing thousands of string replacements in a tight loop.

True - I was simply mentioning the speed difference.

LyokoHaCk · 04-18-08

Thanks guys~!

04-17-08	#1 (permalink)
LyokoHaCk Programmer Join Date: Aug 2006 Location: United States Inc. Posts: 1,976 Rep: 73 Unique Rep: 68 FAQs Submitted: 1 Folding Team Rank: 1802 Trader Rating: 2	Simple Java Trim Help I can't find a way to trim the last character of a StringBuilder or a String for that matter. How can I do it? The is no trimEnd(...) and trim doesn't accept arguments. TY

		Overclock.net - Overclocking.net > Software, Programming and Coding > Coding and Programming
Simple Java Trim Help

04-18-08	#6 (permalink)
LyokoHaCk Programmer Join Date: Aug 2006 Location: United States Inc. Posts: 1,976 Rep: 73 Unique Rep: 68 FAQs Submitted: 1 Folding Team Rank: 1802 Trader Rating: 2	Thanks guys~!

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)