How to remove unnecessary space from a string using regular expression and trim in java

Question

My requirement is remove all unnecessary spaces from a string with using regular expression.

I have a string like this:

"name=john    age=26     year=1999";

I want to remove Unnecessary space between two eliminator, expecting output

"name=john age=26 year=1999;"

i dont think its a good idea trieing to achieve this with regular expressions — deterministicFail, May 23 '14 at 06:46
but how to do with help of regx can you provide some code snip it — user3667783, May 23 '14 at 06:52
@user3667783 there are some correct answers below these comments. — Christian Tapia, May 23 '14 at 06:53

score 4 · Answer 1 · answered May 23 '14 at 06:47

4

account = account.replaceAll("\\s+", " ");

answered May 23 '14 at 06:47

Jainendra

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`" name=john age=26 year=1999 "` gave me one space at the beginning. – Nidheesh May 23 '14 at 07:05
@tailorBird use trim() after the above code `account = account.replaceAll("\\s+", " ").trim();` – Jainendra May 23 '14 at 07:46

Sanjeev · Answer 2 · 2014-05-23T06:53:59.690

0

You can use String#replaceAll and use reg-ex "[ \t]+" to replace multiple space with a single one like this:

 account.replaceAll("[ \t]+", " ");

Hope this helps.

edited May 23 '14 at 06:53

answered May 23 '14 at 06:48

Sanjeev

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This will "fail" on tabs and similar whitespace. – user2864740 May 23 '14 at 06:49
Why the class (`[]`)? – Biffen May 23 '14 at 06:49
I agree with you. but OP only asked for multiple spaces. that's why i just used `[ ]` instead `\\s`. Adding \t to it :) – Sanjeev May 23 '14 at 06:50
@Sanjeev `x+` is the same as `[x]+`, even if `x` is a space. – Biffen May 23 '14 at 06:51
@Biffen agreed just correcting it. Thanks – Sanjeev May 23 '14 at 06:52
`[ \t]` still leaves out a lot of spaces. – Biffen May 23 '14 at 06:55
@Biffen again agree, i can replace it with \\s but then it will be same as other answer. – Sanjeev May 23 '14 at 06:56

Nidheesh · Answer 3 · 2014-05-23T06:58:12.030

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What about this?

    String before ="    name=john   age=26     year=1999  ";  
    String  after = before.replaceAll("\t", " ");
    after = after.trim().replaceAll(" +", " ");
    System.out.println(after);

edited May 23 '14 at 06:58

answered May 23 '14 at 06:51

Nidheesh

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score -3 · Answer 4 · answered May 23 '14 at 06:45

-3

There's a regular expressions for finding space, now just replace it

/\s+/

answered May 23 '14 at 06:45

waplet

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I'm pretty sure that that isn't proper the Java regex for the task... – awksp May 23 '14 at 06:48

How to remove unnecessary space from a string using regular expression and trim in java

4 Answers4