Removing single-letter words using java pattern matching

Question

I want to exclude all single-letter words from a string in Java using pattern matching. I am encoded as follows:

String str = " P@ "; //remove single char words and extra white spaces inputStr = inputStr.replaceAll("\\b[\\w']{1}\\b", "").replaceAll("\\s+", " ").trim(); 

I expect output as P @ since input is not a single letter word. But I get the output as @ because it eliminates P. Thus, basically it only considers alphabetic characters to match the pattern. While I want to match the length of the input string.

Please, help.

Answer 1

Try using this:

  String data = "asd df R# $R $$ $ 435 4ee 4"; String replaceAll = data.replaceAll("(\\s.\\s)|(\\s.$)", " "); System.out.println(replaceAll); 

Output: asd df R# $R $$ 435 4ee

Answer 2

Use this

 str = str.replaceAll("(^.$|\\s.\\s|^.\\s|\\s.$)", "").replaceAll("\\s+", " ").trim(); 

The problem with your solution was that you used \b , which was expecting a character at the end and beginning of a word so that it does not work in your case.

/b

Matches in position between the word character (everything that matches the \ w character) and the non-word character (everything that matches [^ \ w] or \ W), as well as at the beginning and / or end of the line if the first and / or last characters in a string are word characters.

REFER FOR REGULAR EXPRESSION

Answer 3

Try this regex:

 \s([^\s]{1})\s 

You should catch single characters without spaces, marked with a space on both sides. If you need to accept characters without spaces, such as ',' and '.' as separators you will need to add them.

Answer 4

Test case:

asd df R # $ R $$ $ 435 4ee 4 hey buddy this is a test i @wanted

 "[!-~]?\\b[Az]\\b[!-~]?" "[!-~]?\\b[\\w]\\b[!-~]?" 

output for above code:

asd df $$ $ 435 4ee 4 hey buddy this is the test required
asd df $$ $ 435 4ee hey buddy this test wants

note that in the second there are no four. The second regular expression gets rid of numbers that don’t know if one number is counted or not