Which statement is not true about package statements?
Responda
Package statements are optional.
Package statements are limited to one per source file.
Standard Java coding convention for package names reverses the domain name of the organization or group creating the package.
The package names beginning with javas.* and javaw.* are reserved.
Questão 2
Questão
Which statement represents a valid statement that will allow for the inclusion of classes from the java.util package?
Responda
import java.util;
import java.util.*;
#include java.util;
#include java.util.*;
Questão 3
Questão
List four interfaces of the Collections API.
Responda
ArrayList, Map, Set, Queue
List, Map, Set, Queue
List, Map, HashSet, PriorityQueue
List, HashMap, HashSet, PriorityQueue
Questão 4
Questão
Which class in the java.io package allows for the reading and writing of files to specified locations within a file?
Responda
File
FileDescriptor
FilenameFilter
RandomAccessFile
Questão 5
Questão
Which MS Windows–based command-line utility will allow you to run the Java interpreter without launching the console window?
Responda
javaw
interpw
java -wo
jconsole
Questão 6
Questão
What is the correct import package needed to use the ArrayList class?
Responda
import java.awt.*;
import java.io.*;
import java.net.*;
import javax.swing.*;
import java.util.*;
This is a trick question, because it is part of the java.lang package that is imported automatically.
Questão 7
Questão
Of the following packages, which contain classes for building a graphical interface? (Choose all that apply.)
Responda
java.awt
java.io
java.net
javax.swing
java.util
Questão 8
Questão
Which of the following statements is correct?
Responda
A Java class can extend only one superclass.
A Java class can extend multiple superclasses.
A Java class cannot extend any superclasses.
A Java class does not extend superclasses; it implements them.
Questão 9
Questão
You have created a set of classes for your company and would like to include them in a package. Which one of the following would be a valid package name?
Responda
your company name
com.your company name
java.your company name
java.your_company_name
com.your_company_name
Questão 10
Questão
What is the result of running the following command:
javac Simulator.java
Responda
The simulator program would be executed.
A bytecode file Simulator.class would be created.
A bytecode file Simulator.java would be created.
An error would be displayed because this is the wrong syntax.
Questão 11
Questão
Of the following, which types of statements must be used to count the number of nickels in a String array of various coins?
Responda
Assignment
Assertion
Iteration
Conditional
Questão 12
Questão
The following short code segment contains two errors. What are they?
int a = 1;
does
a = 2;
while (a == 1)
Responda
The declaration for the variable a must occur within the dowhile statement.
Braces must be included for do-while statements even when only one statement is enclosed.
There is no does keyword; only the do keyword is allowed as part of a conditional statement.
The do-while statement must end with a semicolon.
Questão 13
Questão
The continue and break statements are allowed within what types of statements?
Responda
Loop statements
All conditional statements
The switch statement
Expression statements
Questão 14
Questão
Select the commenting style that uses symbols designed to work with Javadoc.
Responda
// @author Robert
/* @author Robert */
/** @author Robert */
/** @author Robert ;
Questão 15
Questão
Given the following code segments, which answer is NOT a valid Javaimplementation because it won’t compile?
Responda
int variableA = 10;
float variableB = 10.5f;
int variableC = variableA + variableB;