Removing whitespace from strings in Java

There are a few different ways you can remove whitespace from strings in Java. Here are a few options:

  1. Using the replaceAll method:
String input = "   This is a string with leading and trailing whitespace   ";
String output = input.replaceAll("^\\s+|\\s+$", "");

This will remove all leading and trailing whitespace from the input string.

  1. Using the trim method:
String input = "   This is a string with leading and trailing whitespace   ";
String output = input.trim();

This will also remove leading and trailing whitespace from the input string.

  1. Using the strip method (Java 11 and later):
String input = "   This is a string with leading and trailing whitespace   ";
String output = input.strip();

This method also removes leading and trailing whitespace from the input string.

Note that these methods will only remove leading and trailing whitespace. If you want to remove all whitespace from the string, you can use a regular expression like this:

String input = "   This is a string    with    lots of    whitespace   ";
String output = input.replaceAll("\\s+", "");

This will replace all instances of one or more contiguous whitespace characters with an empty string, effectively removing all the whitespace.