Regex for extracting a substring

Question

I want to extract the string from the input string with "/" removed from the beginning and the end (if present).

For example :

Input String : /abcd Output String : abcd

Input String : /abcd/ Output String : abcd

Input String : abcd/ Output String : abcd

Input String : abcd Output String : abcd

Input String : //abcd/ Output String : /abcd

Google is faster than ask question - stackoverflow.com/questions/2088037/trim-characters-in-java — SergeyS
– SergeyS, Commented Jan 10, 2013 at 9:26

Alex DiCarlo · Accepted Answer · 2013-01-10 09:37:58Z

5

public static void main(String[] args) {
    String abcd1 = "/abcd/";
    String abcd2 = "/abcd";
    String abcd3 = "abcd/";
    String abcd4 = "abcd";
    System.out.println(abcd1.replaceAll("(^/)?(/$)?", ""));
    System.out.println(abcd2.replaceAll("(^/)?(/$)?", ""));
    System.out.println(abcd3.replaceAll("(^/)?(/$)?", ""));
    System.out.println(abcd4.replaceAll("(^/)?(/$)?", ""));
}

Will work.

Matches the first (^/)? means match 0 or 1 '/' at the beginning of the string, and (/$)? means match 0 or 1 '/' at the end of the string.

Make the regex "(^/*)?(/*$)?" to support matching multiple '/':

String abcd5 = "//abcd///";
System.out.println(abcd1.replaceAll("(^/*)?(/*$)?", ""));

edited Jan 10, 2013 at 9:37

answered Jan 10, 2013 at 9:32

Alex DiCarlo

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Comments

Peter L. · Accepted Answer · 2013-01-10 09:37:25Z

0

One more guess: ^\/|\/$ for replace RegEx.

answered Jan 10, 2013 at 9:37

Peter L.

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2 Comments

Peter L. Over a year ago

This one: ^\/+|\/+$ will match /////abcd/////// as well - just in case, but not mentioned in the initial request.

Peter L. Over a year ago

Why downvote? the initial answer seems to match the initial request))) "with "/" removed from the beginning and the end (if present)"

hsz · Accepted Answer · 2013-01-10 09:45:54Z

0

Method without regex:

String input  = "/hello world/";

int length = input.length(),
    from   = input.charAt(0) == '/' ? 1 : 0,
    to     = input.charAt(length - 1) == '/' ? length - 1 : length;

String output = input.substring(from, to);

edited Jan 10, 2013 at 9:45

answered Jan 10, 2013 at 9:37

hsz

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Comments

jmventar · Accepted Answer · 2013-01-10 09:29:53Z

-1

You can try

 String original="/abc/";
 original.replaceAll("/","");

Then do call trim to avoid white spaces.

original.trim();

answered Jan 10, 2013 at 9:29

jmventar

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2 Comments

Chris Seymour Over a year ago

Only from the start and the end of the string, this would remove all.

jmventar Over a year ago

Following his examples seems only char '/' at start/end

mdelpeix · Accepted Answer · 2013-01-10 09:31:16Z

-2

This one seems works :

/?([a-zA-Z]+)/?

Explanation :

/? : zero or one repetition

([a-zA-Z]+) : capture alphabetic caracter, one or more repetition

/? : zero or one repetition

answered Jan 10, 2013 at 9:31

mdelpeix

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