The replaceAll() method of the String class replaces each substring of this string that matches the given regular expression with the given replacement. You can remove white spaces from a string by replacing " " with "".
public class DuplicateCharacters { public static void main(String[] args){ String str = "Hello how are you"; str = str.replaceAll(" ", ""); System.out.println(str); } }
Hellohowareyou