API Contents - SCJP Sun Certified Programmer for Java Platform SE6 - page 325

A regular expression is a sequence of characters that describe a pattern of characters. We
discussed how to represent a regular expression in Java using the compile method of the
Pattern class, and how to search for a match to a Pattern using the matcher method of
the Matcher class. The String.split method splits a String object into an array of String
objects based on a regular expression. The Scanner class is a text scanner that parses primi-
tive data types and strings into tokens using a delimiter, and is also useful for reading key-
board input from the console.
Be sure to test your knowledge of these API contents by answering the Review Questions
at the end of the chapter. Make sure you have a good understanding of the following Exam
Essentials before you attempt the Review Questions.
Exam Essentials
Understand autoboxing and unboxing. Since the addition of autoboxing and unboxing to
Java, the need for using the wrapper classes explicitly has been minimized greatly. Be sure
to understand when a primitive type is autoboxed or unboxed.
Be familiar with the various string methods. The concat method in String creates a new
String object. Understand how the append and insert methods of StringBuilder and
StringBuffer behave.
Be familiar with the basic methods of the File class. The java.io.File class only repre-
sents a pathname to a fi le or directory and does not contain any methods for accessing or
modifying the contents of a fi le. However, you can use the File class to create and delete
fi les and directories.
Understand Java object serialization. Understand what it means for an object to be seri-
alizable and how to serialize and deserialize an object using the ObjectOutputStream and
ObjectInputStream classes.
Know how to format and parse numbers, currency, and dates for a given locale. You
won't be expected know all the foreign locales, but you should be able to format or parse a
number, currency, or date in the U.S. locale using the NumberFormat , DecimalFormat , and
DateFormat classes in java.text .
Be able to interpret simple regular expressions. Know the patterns and metacharacters
you need to for the exam. You won't see a complex and confusing regular expression on the
exam, but you should be able to answer questions that contain simple regular expressions
used in places like Pattern , Scanner , and String.split .
Understand the format specifiers for format / printf . Expect to see a question or two
on the exam that uses the format specifi ers found in the format/printf methods of the
PrintWriter and Formatter classes. The exam objectives specifi cally list %b , %c , %d , %f ,
and %s .