SCJP Mock Exam 2(2)
添加时间: 2007-9-24 22:39:48 作者: JAVA题库 阅读次数:313 来源: http://www.d9soft.com
Question 19)
Which of the following are true?
1) A component may have only one event listener attached at a time
2) An event listener may be removed from a component
3) The ActionListener interface has no corresponding Adapter class
4) The processing of an event listener requires a try/catch block
Answer to Question 19)
--------------------------------------------
Question 20)
Which of the following are Java keywords?
1) sizeof
2) main
3) transient
4) volatile
Answer to Question 20)
------------------------------------------
Question 21)
Which of the following statements are true?
1) The default constructor has a return type of void
2) The default constructor takes a parameter of void
3) The default constructor takes no parameters
4) The default constructor is not created if the class has any constructors of its own.
Answer to Question 21)
--------------------------------------
Question 22)
Which of the following statements are true?
1) All of the variables in an interface are implicitly static
2) All of the variables in an interface are implicitly final
3) All of the methods in an interface are implicitly abstract
4) A method in an interface can access class level variables
Answer to Question 22)
---------------------------------------
Question 23)
Which of the following statements are true?
1 ) The String class is implemented as a char array, elements are addressed using the stringname[] convention
2) The + operator is overloaded for concatenation for the String class
3) Strings are a primitive type in Java and the StringBuffer is used as the matching wrapper type
4) The size of a string can be retrieved using the length property
Answer to Question 23)
----------------------------------------
Question 24)
Which of the following statements are true?
1) A method in an interface must not have a body
2) A class may extend one other class plus at most one interface
3) A class may extends at most one other class plus implement many interfaces
4) An class accesses an interface via the keyword uses
Answer to Question 24)
---------------------------------------------
Question 25)
Which of the following statements are true?
1) The following statement will produce a result of 1. System.out.println( -1 >>>2);
2) Performing an unsigned left shift (<<<) on a negative number will always produce a negative number result
3) The following statement will produce a result of zero, System.out.println(1 >>1);
4) All the integer primitives in java are signed numbers
Answer to Question 25)
-------------------------------------------
Question 26)
Which of the following statements are true?
1) The elements in a Java array can only be of primitive tray can only be of primitive types, not objects
2) Arrays are initialized to default values wherever they are created
3) An array may be dynamically resized using the setSize method
4) You can find out the size of an array using the size method
Answer to Question 26)
-----------------------------------------
Question 27)
Given the following class
public class Ombersley{
public static void main(String argv[]){
boolean b1 = true;
if((b1 ==true) place(true)){
System.out.println("Hello Crowle");
}
}
public static boolean place(b public static boolean place(boolean location){
if(location==true){
System.out.println("Borcetshire");
}
System.out.println("Powick");
return true;
turn true;
}
}
What will happen when you attempt to compile and run it?
1) Compile time error
2) Output of "Hello Crowle"
3) Output of Hello Crowle followed by Borcetshire and Powick
4) No output
Answer to Question 27)
--------------------------------------------
Question 28)
You are given a class hierarchy with an instance of the class Dog. The class Dog is a child of mammal and the class Mammal is a child of the class Vertebrate. The class Vertebrate has a method called move which prints out the string "move". The class mammal overrides this method and prints out the string "walks". The class Dog overrides this method and prints out the string "walks on paws". Given an instance of the class Dog,. how can you access the ancestor method move in Vertebrate so it prints out the string "move";
1) d.super().super().move();
2) d.parent().parent().move();
3) d.move();
4) none of the above;
Answer to Question 28)
-----------------------------------------
Question 29)
Which of the following most closely describes the process of overriding?
1) A class with the same name replaces the functionality of a class defined earlier in the hierarchy
2) A method with the same name completely replaces the functionality of a method earlier in the hierarchy
3) A method with the same name but different parameters gives multiple uses for the same method name
4) A class is prevented from accessing methods in its immediate ancestor
Answer to Question 29)
-------------------------------------------------
Question 30)
Which of the following statements are true?
1) The % is used to calculate a percentage thus: 10 % 20=50
2) The / operator is used to divide one value by another
3) The # symbol may not be used as the first character of a variable
4) The $ symbol may not be used as the first character of a variable
Answer to Question 30)
---------------------------------------
Question 31)
Which of the following statements are true?
1) The default layout manager for an Applet is FlowLayout
2) The default layout manager for a Frame is FlowLayout
3) A layout manager must be assigned to an Applet before the setSize method is called
4) The FlowLayout manager attempts to honor the preferred size of any components
Answer to Question 31)
---------------------------------
Question 32)
Which of the following statements are true about a variable created with the static modifier?
1) Once assigned the value of a static variable may not be altered
2) A static variable created in a method will keep the same value between calls
3) Only one instance of a static variable will exist for any amount of class instances
4) The static modifier can only be applied to a primitive value
Answer to Question 32)
--------------------------------
Question 33)
Which of the following statements are true?
1) Java uses a system called UTF for I/O to support international character sets
2) The RandomAccessFile is the most suitable class for supporting international character sets
3) An instance of FileInputStream may not be chained to an instance of FileOutputStream
4) File I/O activities requires use of Exception handling
Answer to Question 33)
Question 34)
What will happen when you attempt to compile and run the following code?
import java.io.*;
class ExBase{
abstract public void martley(){
}
}
public class MyEx extends ExBase{
public static void main(String argv[]){
DataInputStream fi = new DataInputStream(System.in);
try{
fi.readChar();
}catch(IOException e){
System.exit(0);
}
finally {System.out.println("Doing finally");}
}
}
1) Compile time error
2) It will run, wait for a key press and then exit
3) It will run, wait for a keypress, print "Doing finally" then exit
4) At run and immediately exit
Answer to Question 34)
---------------------------------------
Question 35)
What will happen when you attempt to compile and run the following code
public class Borley extends Thread{
public static void main(String argv[]){
Borley b = new Borley();
b.start();
}
public void run(){
System.out.println("Running");
}
}
1) Compilation and run but no output
2) Compilation and run with the output "Running"
3) Compile time error with complaint of no Thread target
4) Compile time error with complaint of no access to Thread package
Answer to Question 35)
-------------------------------------------
Question 36)
Assuming any exception handling has been set up, which of the following will create an instance of the RandomAccessFile class
1) RandomAccessFile raf=new RandomAccessFile("myfile.txt","rw");
2) RandomAccessFile raf=new RandomAccessFile( new DataInputStream());
3) RandomAccessFile raf=new RandomAccessFile("myfile.txt");
4) RandomAccessFile raf=new RandomAccessFile( new File("myfile.txt"));
Answer to Question 36)
---------------------------------------
Question 37)
Given the following class definition
public class Upton{
public static void main(String argv[]){
}
public void amethod(int i){}
//Here
}
Which of the following would be legal to place after the comment //Here ?
1) public int amethod(int z){}
2) public int amethod(int i,int j){return 99;}
3) protected void amethod(long l){ }
4) private void anothermethod(){}
Answer to Question 37)
------------------------------------------------
Question 38)
Which of the following statements are true?
1) Code must be written if the programmer wants a frame to close on selecting the system close menu
2) The default layout for a Frame is the BorderLayout Manager
3) The layout manager for a Frame cannot be changed once it has been assigned
4) The GridBagLayout manager makes extensive use of the the GridBagConstraints class.
Answer to Question 38)
---------------------------------------
Question 39)
Given the following class definition
public class Droitwich{
class one{
private class two{
public void main(){
System.out.println("two");
}
}
}
}
Which of the following statements are true
1) The code will not compile because the classes are nested to more than one level
2) The code will not compile because class two is marked as private
3) The code will compile and output the string two at runtime
4) The code will compile without error
Answer to Question 39)
-----------------------------------
Question 40)
Given the following code
class Base{
static int oak=99;
}
public class Doverdale extends Base{
public static void main(String argv[]){
Doverdale d = new Doverdale();
d.amethod();
}
public void amethod(){
//Here
}
}
Which of the following if placed after the comment //Here, will compile and modify the value of the variable oak?
上一篇文章: SCJP Mock Exam 2(1) 下一篇文章:
相关文章:
相关软件: