Revised: Wed May 11 17:31:29 CDT 2016
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Table of Contents
Preface
This module contains review questions and answers keyed to the module titled Java4210: Getting Started with Generics .
The questions and the answers are connected by hyperlinks to make it easy for you to navigate from the question to the answer and back again.
Questions
Question 1 .
True or False: When Java version 1.5 was released, it contained many new language features, including:
- Generics
- Enhanced for Loop
- Autoboxing/Unboxing
- Collections
- Typesafe Enums
- Varargs
- Static Import
- Metadata
Question 2
True or False: Using Java version1.7, the code shown in Listing 1 will compile without warnings, errors, or other messages being generated by thecompiler.
| Listing 1 - Question 2 |
|---|
/*File Q02.java
************************************************/import java.util.*;
public class Q02{ArrayList var1 = new ArrayList();void runIt(){
var1.add(new Date());//Note the required cast in the following
// statement.System.out.println(
((Date)var1.get(0)).getTime());}//runIt
public static void main(String[]args){
new Q02().runIt();}//end main}//end class Q02
//=============================================// |
Question 3
Generics was introduced in Java v1.5 to provide which of the following:
- A. Code simplicity
- B. Compile-time type safety
- C. A clear and straightforward code syntax.
- D. None of the above.
Question 4
True or False: The use of generics is limited to the Java Collections framework.
Question 5
True or False: The Java v1.7 compiler produces an error message when an attempt is made to compile the code shown in Listing 1 .
Question 6
True or False: When the code in Listing 1 is compiled using the -Xlint:unchecked switch with Java v1.7, the compiler produces:
- A. An error message
- B. A warning
- C. None of the above
Question 7
True or False: The program code shown in Listing 2 will compile and execute successfully to produce an output similar to that shownin Figure 1 .
| Listing 2 - Question 7. |
|---|
/*File Q07.java
************************************************/import java.util.*;
public class Q07{ArrayList var1 = new ArrayList();void runIt(){
var1.add(new Date());System.out.println(
(var1.get(0)).getTime());}//runIt
public static void main(String[]args){
new Q07().runIt();}//end main}//end class Q07
//=============================================// |
| Figure 1 - Question 7. |
|---|
1378054267172 |
Question 8
What modification must be made to the code shown in Listing 2 to cause it to compile and execute successfully?