How do I remove a repeating characted in my string and trim the white spaces within a string in Java?

Question

I have to test few 10 digit values.

          Value: 124324*3213*4324*44*3123**13*
         Expected value: 1243243213432444312313

So far, I have been able to replace the stars using str.replace() function. But I'm unable to remove the white spaces created after removing the star ?.

Please add the code you've tried. To replace something by removing it instead of adding space try: str.replace('*', ''); — JFPicard, Nov 19 '15 at 17:39
Using this: value = value.replace(value.charAt(lastIndexof('*'),'\u0000'); — Gautham Honnavara, Nov 19 '15 at 17:40
So you only need the asterisk(*) characters removed not the duplicate numbers also? — Perdomoff, Nov 19 '15 at 17:58

score 2 · Answer 1 · answered Nov 19 '15 at 17:40

2

Try something like this:

String value = "124324*3213*4324*44*3123**13*".replace("*", "");

answered Nov 19 '15 at 17:40

Mateusz Korwel

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@GauthamHonnavara Have you tried it? Have you looked at the docs? – Taelsin Nov 19 '15 at 17:43
No, `String.replace` method allows `char` or `CharSequence` parameters: https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#replace-java.lang.CharSequence-java.lang.CharSequence- – Mateusz Korwel Nov 19 '15 at 17:45
Yes, it worked for me. Thanks a ton. But, could you please tell me is charSequence considered a string. – Gautham Honnavara Nov 19 '15 at 17:46
Also, is there a way to just remove the last occurence of *(something like the last index) but keep the remaining ones. – Gautham Honnavara Nov 19 '15 at 17:47
Do you mean something like this? http://stackoverflow.com/questions/16665387/replace-last-occurrence-of-a-character-in-a-string – Mateusz Korwel Nov 19 '15 at 17:55

score 2 · Accepted Answer · answered Nov 19 '15 at 17:41

2

Remember that strings are immutable in Java so you have to assign value again:

String s = "124324*3213*4324*44*3123**13*";
s = s.replaceAll("\\*", "");

"\\*" - is a regular expression, but you don't need to worry about that. The important part is that "*" sign has special meaning in regular expressions, so you have to escape it with a backslash. To create a backslash character in Java string you have to use "\\" - so the final expression is "\\*".

answered Nov 19 '15 at 17:41

Keammoort

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s = s.replace("*", ""); would also suffice – Taelsin Nov 19 '15 at 17:46
@Taelsin you're right, perhaps using a regular expression is a bit too complicated for such simple task. – Keammoort Nov 19 '15 at 17:47
Thanks a lot for the solution, is there a way I can remove only the last occurence of *. Like removing the index of that *. – Gautham Honnavara Nov 19 '15 at 18:42

How do I remove a repeating characted in my string and trim the white spaces within a string in Java?

2 Answers2