Review Questions :: Chapter 10. Fundamental Classes :: A programmer's guide to Java Certification :: Misc

Review Questions

10.4	Which of the following are wrapper classes? Select the three correct answers. `java.lang.Void` `java.lang.Int` `java.lang.Boolean` `java.lang.Long` `java.lang.String`
10.5	Which of the following classes do not extend the `java.lang.Number` class? Select the two correct answers. `java.lang.Float` `java.lang.Byte` `java.lang.Character` `java.lang.Boolean` `java.lang.Short`
10.6	Which of these classes define immutable objects? Select the three correct answers. `Character` `Byte` `Thread` `Short` `Object`
10.7	Which of these classes have a one-parameter constructor taking a string? Select the two correct answers. `Void` `Integer` `Boolean` `Character` `Object`
10.8	Which of the wrapper classes have a `booleanValue()` method? Select the one correct answer. All wrapper classes. All wrapper classes except `Void`. All wrapper classes that also implement the `compareTo()` method. All wrapper classes extending `Number`. Only the class `Boolean`.
10.9	Which statements are true about wrapper classes? Select the two correct answers. `String` is a wrapper class. `Double` has a `compareTo()` method. `Character` has a `intValue()` method. `Byte` extends `Number`.