String processing

In mainstream programming, String probably is the most popular class. In Chapter 1, Getting Started with Java 17, we learned about this class, its literals, and its specific feature called string immutability. In this section, we will explain how a string can be processed using the String class methods and utility classes from the standard library, and the StringUtils class from the org.apache.commons.lang3 package in particular.

Methods of the String class

The String class has more than 70 methods that enable analyzing, modifying, and comparing strings, and converting numeric literals into the corresponding string literals. To see all the methods of the String class, please refer to the Java API online at https://docs.oracle.com/en/java/javase.

String analysis

The length() method returns the number of characters in the string, as shown in the following code:

String s7 = "42";

System.out.println(s7.length());    //prints...