Java regex for specific case

Question

I am trying to reformat a string to my desired format. I have been trying to figure this out for a while but I can't think of any elegant solution using regexs. I have come up with a solution using String's indexOf() and replace() but it's not exactly pretty.

I want to convert any string so that there is exactly one space on each side of the "-".

Possible inputs:

"abc- abc"
"abc -abc"
"abc - abc"
"abc-abc"

and each case should be converted to

"abc - abc"

Thanks for any help. Let me know if you need more clarification.

Even if your initial solution wasn't pretty, you should still show it as part of the question. It demonstrates that you at least tried something. — p.s.w.g
– p.s.w.g, Commented Jul 18, 2013 at 3:08

falsetru · Accepted Answer · 2013-07-18 03:07:12Z

2

Using \s*-\s* pattern:

"abc- abc".replaceAll("\\s*-\\s*", " - "))

answered Jul 18, 2013 at 3:07

falsetru

371k69 gold badges770 silver badges660 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Luiggi Mendoza · Accepted Answer · 2013-07-18 03:07:44Z

1

Using String#replaceAll:

String pattern = "\\s*-\\s*";
String s1 = "abc- abc";
String s2 = "abc -abc";
String s3 = "abc - abc";
String s4 = "abc-abc";
System.out.println(s1.replaceAll(pattern, " - "));
System.out.println(s2.replaceAll(pattern, " - "));
System.out.println(s3.replaceAll(pattern, " - "));
System.out.println(s4.replaceAll(pattern, " - "));

Explanation of "\\s*-\\s*" regex:

\\s => space (in fact, is \s but Java needs double \\)
* => 0 or more
- => simple '-'

More info about Regular Expressions: Regular Expression Basic Syntax Reference

answered Jul 18, 2013 at 3:07

Luiggi Mendoza

85.9k16 gold badges160 silver badges355 bronze badges

1 Comment

btse Over a year ago

doh, I'm an idiot. I was using \\S instead of \\s which is why mine wasn't working.

p.s.w.g · Accepted Answer · 2013-07-18 03:06:37Z

1

The simplest would probably be to use this pattern:

[ ]?-[ ]?

Like this:

str = str.replaceAll("[ ]?-[ ]?", " - ");

answered Jul 18, 2013 at 3:06

p.s.w.g

150k31 gold badges307 silver badges339 bronze badges

Collectives™ on Stack Overflow

Java regex for specific case

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related