regular expression remove () brases

Question

String abc=folderDocBean.getService().replaceAll("\\s+", "_");

abc = hello world (English) or hello world ((((English

expected output:- hello_world_English

In the above line it removes white spaces and ads _ in the place of whitespace..

I want to remove the braces if matching braces () exists then all braces the braces need to remove.

I have tried with abc.replaceAll("\\p{P}",""); is removing the braces but not ading any underscore to my string

abc = abc.replaceAll("\\s+", "_");
        abc = abc.replaceAll("[\\(\\)\\[\\]\\{\\}]",""); ==> it is satisfying my reqirement and how can I write the same in a single statement

see how to use `[]` in regex to replace more than one character — AxelH, Mar 16 '18 at 07:07
Just to clarify: You want to remove the braces if matching braces(1 open 1 close) exists, all braces, or the content between matching braces? — sn42, Mar 16 '18 at 07:07
Possible duplicate of [how to remove brackets character in string (java)](https://stackoverflow.com/questions/25852961/how-to-remove-brackets-character-in-string-java) — xingbin, Mar 16 '18 at 07:10
@sn42 I want to remove the braces if matching braces(1 open 1 close) exists, all braces — user9130953, Mar 16 '18 at 07:13
You should really update your question with some clear defintions on what is supposed to happen. For example what would happen with `hello world ((((English`? — Ben, Mar 16 '18 at 07:15
Two input, only one output .... see how to create a [mcve] ... — AxelH, Mar 16 '18 at 07:26
@WiktorStribiżew `abc.replaceAll("\\p{P}","");` is removing the braces but not ading any underscore to my string — user9130953, Mar 16 '18 at 07:29
You might try: `string.replaceAll("\\s+\\(+|\\s+", "_").replaceAll("\\)+", "");`. — DevilsHnd - 退職した, Mar 16 '18 at 07:40
[My suggestion works well](https://ideone.com/f8f4UU). *it is satisfying my reqirement and how can I write the same in a single statement* - it will look ugly in Java, I do not recommend it. — Wiktor Stribiżew, Mar 16 '18 at 07:42
@WiktorStribiżew it is working well. I have not tested good.my apologies — user9130953, Mar 16 '18 at 07:46
can you please post the same as answer and explain something about that regex — user9130953, Mar 16 '18 at 07:47
May be a duplicate of https://stackoverflow.com/a/34207035/8089107 — sn42, Mar 16 '18 at 07:47
Possible duplicate of [how to replace multiple matched Regex](https://stackoverflow.com/questions/34180794/how-to-replace-multiple-matched-regex) — sn42, Mar 16 '18 at 07:48
@Wiktor Stribiżew - Your suggestion may work well but that's a matter of opinion. Your suggestion also removes **ALL** non-word characters (not just parentheses) from the string the expression is working against. — DevilsHnd - 退職した, Mar 16 '18 at 07:59

score 1 · Accepted Answer · answered Mar 16 '18 at 08:00

You can write the replacement using a single expression [()\\[\\]{}|]|\\s+, but that will require using a StringBuffer. Here is how you can do it:

public static void main(String[] args) {
    String abc = "hello world ((((English)) {test}";
    Pattern pat = Pattern.compile("[()\\[\\]{}|]|\\s+");
    Matcher m = pat.matcher(abc);
    StringBuffer bufStr = new StringBuffer();
    while(m.find()) {
        m.appendReplacement(bufStr, m.group().contains(" ") ? "_" : "");
    }
    m.appendTail(bufStr);
    System.out.println(bufStr);
}

So basically you have a combined regular expression which intercepts all brackets or multiple spaces and then you loop through all matches and whenever a match is found you analyse the match with m.group().contains(" "). According to whether the match contains a space or not you append either "_" or an empty string.

If you run the code above you will get this output:

hello_world_English_test

regular expression remove () brases

1 Answers1