From the Sun Certified Programmer for
Java 2 Platform 1.4 exam objectives:
Section 8: Fundamental Classes in the java.lang Package
# Write code using the following methods of the java.lang.Math class: abs, ceil, floor, max, min, random, round, sin, cos, tan, sqrt.
# Describe the significance of the immutability of String objects.
# Describe the significance of wrapper classes, including making appropriate selections in the wrapper classes to suit specified behavior requirements, stating the result of executing a fragment of code that includes an instance of one of the wrapper classes, and writing code using the following methods of the wrapper classes (e.g., Integer, Double, etc.):
# o doubleValue
# o floatValue
# o intValue
# o longValue
# o parseXxx
# o getXxx
# o toString
# o toHexString
If you want a reason why class Byte has no charValue() method, consider that a byte can be negative while a char can not.