user1201779 user1201779 - 1 year ago 64
Java Question

How to remove 3 or more consecutive letters in java into 2 consecutive letters?

I'm trying to process strings with repeated chars in order to find the correct word in a dictionary.

The approach I must use is to find words with 3 or more consecutive letters and remove them into 2 consecutive letters.

Then I'll look for in the dictionary if this word exists. If the word doesn't exist, then I must remove the two consecutive letters into 1 letter only.


gooooooood -> good (this existis)
awesooooome -> awesoome (this doesn't exist) -> awesome (this exists)
aaawwwesooooooommmme -> aawwesoomme (this doesn't exist) -> awesome (this exists)

I'm working with JAVA and i'm already using this regular expression to get the words with 3 or more repeated letters in a string:

Pattern p = Pattern.compile("\\b\\w*(\\w)\\1{2}\\w*");

Answer Source

You can use this regex ("pure version"):


String version:


You should use replaceAll(regex, "$1$2$2$3")


(\b\w*?) // capture group 1 is lazy
(\w)     // capture group 2 captures the first occurrence of the char
\2{2,}   // char may occur 2 or more times...
(\w*)    // capture group 3

Note that the $number in the replacement refers to the contents of the corresponding capture group.