Summary

In this chapter, you learned that Strings are immutable sequences of characters. The new operator is optional. The concatenation operator (+) creates a new String with the content of the first String followed by the content of the second String. If either operand involved in the + expression is a String, concatenation is used; otherwise, addition is used. String literals are stored in the string pool. The String class has many methods. You need to know charAt(), concat(), endsWith(), equals(), equalsIgnoreCase(), indexOf(), length(), replace(), startsWith(), substring(), toLowerCase(), toUpperCase(), and trim().

StringBuilders are mutable sequences of characters. Most of the methods return a reference to the current object to allow method chaining. The StringBuilder class has many methods. You need to know append(), charAt(), delete(), deleteCharAt(), indexOf(), insert(), length(), reverse(), substring(), and toString(). StringBuffer is the same as StringBuilder except that it...