Java Coding Problems

8. Removing white spaces from a string

The solution to this problem consists of using the String.replaceAll() method with the \s regular expression. Mainly, \s removes all white spaces, including the non-visible ones, such as \t, \n, and \r:

public static String removeWhitespaces(String str) {  return str.replaceAll("\\s", "");}

Starting with JDK 11, String.isBlank() checks whether the string is empty or contains only white space code points. For third-party library support, please consider Apache Commons Lang, StringUtils.deleteWhitespace(), and the Spring Framework, StringUtils.trimAllWhitespace().