public void foo( boolean a, boolean b)
{
if( a )
{
System.out.println("A"); /* Line 5 */
}
else if(a && b) /* Line 7 */
{
System.out.println( "A && B");
}
else /* Line 11 */
{
if ( !b )
{
System.out.println( "notB") ;
}
else
{
System.out.println( "ELSE" ) ;
}
}
}
Which is a valid declaration within an interface?
What is the widest valid returnType for methodA in line 3?
public class ReturnIt
{
returnType methodA(byte x, double y) /* Line 3 */
{
return (long)x / y * 2;
}
}
You want a class to have access to members of another class in the same package. Which is the most restrictive access that accomplishes this objective?
System.out.print("Start ");
try
{
System.out.print("Hello world");
throw new FileNotFoundException();
}
System.out.print(" Catch Here "); /* Line 7 */
catch(EOFException e)
{
System.out.print("End of file exception");
}
catch(FileNotFoundException e)
{
System.out.print("File not found");
}
and given that EOFException and FileNotFoundException are both subclasses of IOException, and further assuming this block of code is placed into a class, which statement is most true concerning this code?
Which statement is true?
What will be the output of the program?
public abstract class AbstractTest
{
public int getNum()
{
return 45;
}
public abstract class Bar
{
public int getNum()
{
return 38;
}
}
public static void main (String [] args)
{
AbstractTest t = new AbstractTest()
{
public int getNum()
{
return 22;
}
};
AbstractTest.Bar f = t.new Bar()
{
public int getNum()
{
return 57;
}
};
System.out.println(f.getNum() + " " + t.getNum());
}
}
What will be the output of the program?
public class HorseTest
{
public static void main (String [] args)
{
class Horse
{
public String name; /* Line 7 */
public Horse(String s)
{
name = s;
}
} /* class Horse ends */
Object obj = new Horse("Zippo"); /* Line 13 */
Horse h = (Horse) obj; /* Line 14 */
System.out.println(h.name);
}
} /* class HorseTest ends */
What will be the output of the program?
public class Foo
{
Foo()
{
System.out.print("foo");
}
class Bar
{
Bar()
{
System.out.print("bar");
}
public void go()
{
System.out.print("hi");
}
} /* class Bar ends */
public static void main (String [] args)
{
Foo f = new Foo();
f.makeBar();
}
void makeBar()
{
(new Bar() {}).go();
}
}/* class Foo ends */
Which statement is true about a static nested class?
Which is true about a method-local inner class?
Which is true about an anonymous inner class?
Which three statements are true?
1.Assertion checking is typically enabled when a program is deployed.
2.It is never appropriate to write code to handle failure of an assert statement.
3.Assertion checking is typically enabled during program development and testing.
4.Assertion checking can be selectively enabled or disabled on a per-package basis, but not on a per-class basis.
5.Assertion checking can be selectively enabled or disabled on both a per-package basis and a per-class basis.
Which of the following statements is true?
What will be the output of the program?
public class RTExcept
{
public static void throwit ()
{
System.out.print("throwit ");
throw new RuntimeException();
}
public static void main(String [] args)
{
try
{
System.out.print("hello ");
throwit();
}
catch (Exception re )
{
System.out.print("caught ");
}
finally
{
System.out.print("finally ");
}
System.out.println("after ");
}
}
What will be the output of the program?
class SC2
{
public static void main(String [] args)
{
SC2 s = new SC2();
s.start();
}
void start()
{
int a = 3;
int b = 4;
System.out.print(" " + 7 + 2 + " ");
System.out.print(a + b);
System.out.print(" " + a + b + " ");
System.out.print(foo() + a + b + " ");
System.out.println(a + b + foo());
}
String foo()
{
return "foo";
}
}
What will be the output of the program?
public class TestDogs
{
public static void main(String [] args)
{
Dog [][] theDogs = new Dog[3][];
System.out.println(theDogs[2][0].toString());
}
}
class Dog { }
Which three are legal array declarations?
1.int [] myScores [];
2.char [] myChars;
3.int [6] myScores;
4.Dog myDogs [];
5.Dog myDogs [7];
Which one of these lists contains only Java programming language keywords?
Which four options describe the correct default values for array elements of the types indicated?
1.int -> 0
2.String -> "null"
3.Dog -> null
4.char -> '\u0000'
5.float -> 0.0f
6.boolean -> true
Total number of questions : 20
Number of answered questions : 0
Number of unanswered questions : 20
public void foo( boolean a, boolean b)
{
if( a )
{
System.out.println("A"); /* Line 5 */
}
else if(a && b) /* Line 7 */
{
System.out.println( "A && B");
}
else /* Line 11 */
{
if ( !b )
{
System.out.println( "notB") ;
}
else
{
System.out.println( "ELSE" ) ;
}
}
}
Your Answer : (Not Answered)
Correct Answer : C
Option C is correct. The output is "ELSE". Only when a is false do the output lines after 11 get some chance of executing.
Option A is wrong. The output is "A". When a is true, irrespective of the value of b, only the line 5 output will be executed. The condition at line 7 will never be evaluated (when a is true it will always be trapped by the line 12 condition) therefore the output will never be "A && B".
Option B is wrong. The output is "A". When a is true, irrespective of the value of b, only the line 5 output will be executed.
Option D is wrong. The output is "notB".
Which is a valid declaration within an interface?
Your Answer : (Not Answered)
Correct Answer : A
(A) is valid interface declarations.
(B) and (C) are incorrect because interface variables cannot be either protected or transient. (D) is incorrect because interface methods cannot be final or static.
What is the widest valid returnType for methodA in line 3?
public class ReturnIt
{
returnType methodA(byte x, double y) /* Line 3 */
{
return (long)x / y * 2;
}
}
Your Answer : (Not Answered)
Correct Answer : A
However A, B and C are all wrong. Each of these would result in a narrowing conversion. Whereas we want a widening conversion, therefore the only correct answer is D. Don't be put off by the long cast, this applies only to the variable x and not the rest of the expression. It is the variable y (of type double) that forces the widening conversion to double.
Java's widening conversions are:
- From a byte to a short, an int, a long, a float, or a double.
- From a short, an int, a long, a float, or a double.
- From a char to an int, a long, a float, or a double.
- From an int to a long, a float, or a double.
- From a long to a float, or a double.
- From a float to a double.
You want a class to have access to members of another class in the same package. Which is the most restrictive access that accomplishes this objective?
Your Answer : (Not Answered)
Correct Answer : D
The only two real contenders are C and D. Protected access Option C makes a member accessible only to classes in the same package or subclass of the class. While default access Option D makes a member accessible only to classes in the same package.
System.out.print("Start ");
try
{
System.out.print("Hello world");
throw new FileNotFoundException();
}
System.out.print(" Catch Here "); /* Line 7 */
catch(EOFException e)
{
System.out.print("End of file exception");
}
catch(FileNotFoundException e)
{
System.out.print("File not found");
}
and given that EOFException and FileNotFoundException are both subclasses of IOException, and further assuming this block of code is placed into a class, which statement is most true concerning this code?
Your Answer : (Not Answered)
Correct Answer : A
Line 7 will cause a compiler error. The only legal statements after try blocks are either catch or finally statements.
Option B, C, and D are incorrect based on the program logic described above. If line 7 was removed, the code would compile and the correct answer would be Option B.
Which statement is true?
Your Answer : (Not Answered)
Correct Answer : C
This is a great way to think about when objects can be garbage collected.
Option A and B assume guarantees that the garbage collector never makes.
Option D is wrong because of the now famous islands of isolation scenario.
What will be the output of the program?
public abstract class AbstractTest
{
public int getNum()
{
return 45;
}
public abstract class Bar
{
public int getNum()
{
return 38;
}
}
public static void main (String [] args)
{
AbstractTest t = new AbstractTest()
{
public int getNum()
{
return 22;
}
};
AbstractTest.Bar f = t.new Bar()
{
public int getNum()
{
return 57;
}
};
System.out.println(f.getNum() + " " + t.getNum());
}
}
Your Answer : (Not Answered)
Correct Answer : A
You can define an inner class as abstract, which means you can instantiate only concrete subclasses of the abstract inner class. The object referenced by the variable t is an instance of an anonymous subclass of AbstractTest, and the anonymous class overrides the getNum() method to return 22. The variable referenced by f is an instance of an anonymous subclass of Bar, and the anonymous Bar subclass also overrides the getNum() method (to return 57). Remember that to instantiate a Bar instance, we need an instance of the enclosing AbstractTest class to tie to the new Bar inner class instance. AbstractTest can't be instantiated because it's abstract, so we created an anonymous subclass (non-abstract) and then used the instance of that anonymous subclass to tie to the new Bar subclass instance.
What will be the output of the program?
public class HorseTest
{
public static void main (String [] args)
{
class Horse
{
public String name; /* Line 7 */
public Horse(String s)
{
name = s;
}
} /* class Horse ends */
Object obj = new Horse("Zippo"); /* Line 13 */
Horse h = (Horse) obj; /* Line 14 */
System.out.println(h.name);
}
} /* class HorseTest ends */
Your Answer : (Not Answered)
Correct Answer : B
The code in the HorseTest class is perfectly legal. Line 13 creates an instance of the method-local inner class Horse, using a reference variable declared as type Object. Line 14 casts the Horse object to a Horse reference variable, which allows line 15 to compile. If line 14 were removed, the HorseTest code would not compile, because class Object does not have a name variable.
What will be the output of the program?
public class Foo
{
Foo()
{
System.out.print("foo");
}
class Bar
{
Bar()
{
System.out.print("bar");
}
public void go()
{
System.out.print("hi");
}
} /* class Bar ends */
public static void main (String [] args)
{
Foo f = new Foo();
f.makeBar();
}
void makeBar()
{
(new Bar() {}).go();
}
}/* class Foo ends */
Your Answer : (Not Answered)
Correct Answer : C
Option C is correct because first the Foo instance is created, which means the Foo constructor runs and prints "foo". Next, the makeBar() method is invoked which creates a Bar, which means the Bar constructor runs and prints "bar", and finally the go() method is invoked on the new Bar instance, which means the go() method prints "hi".
Which statement is true about a static nested class?
Your Answer : (Not Answered)
Correct Answer : B
Option B is correct because a static nested class is not tied to an instance of the enclosing class, and thus can't access the nonstatic members of the class (just as a static method can't access nonstatic members of a class).
Option A is incorrect because static nested classes do not need (and can't use) a reference to an instance of the enclosing class.
Option C is incorrect because static nested classes can declare and define nonstatic members.
Option D is wrong because it just is. There's no rule that says an inner or nested class has to extend anything.
Which is true about a method-local inner class?
Your Answer : (Not Answered)
Correct Answer : B
Option B is correct because a method-local inner class can be abstract, although it means a subclass of the inner class must be created if the abstract class is to be used (so an abstract method-local inner class is probably not useful).
Option A is incorrect because a method-local inner class does not have to be declared final (although it is legal to do so).
C and D are incorrect because a method-local inner class cannot be made public (remember-you cannot mark any local variables as public), or static.
Which is true about an anonymous inner class?
Your Answer : (Not Answered)
Correct Answer : C
Option C is correct because the syntax of an anonymous inner class allows for only one named type after the new, and that type must be either a single interface (in which case the anonymous class implements that one interface) or a single class (in which case the anonymous class extends that one class).
Option A, B, D, and E are all incorrect because they don't follow the syntax rules described in the response for answer Option C.
Which three statements are true?
1.Assertion checking is typically enabled when a program is deployed.
2.It is never appropriate to write code to handle failure of an assert statement.
3.Assertion checking is typically enabled during program development and testing.
4.Assertion checking can be selectively enabled or disabled on a per-package basis, but not on a per-class basis.
5.Assertion checking can be selectively enabled or disabled on both a per-package basis and a per-class basis.
Your Answer : (Not Answered)
Correct Answer : B
(1) is wrong. It's just not true.
(2) is correct. You're never supposed to handle an assertion failure.
(3) is correct. Assertions let you test your assumptions during development, but the assertion code—in effect—evaporates when the program is deployed, leaving behind no overhead or debugging code to track down and remove.
(4) is wrong. See the explanation for (5) below.
(5) is correct. Assertion checking can be selectively enabled or disabled on a per-package basis. Note that the package default assertion status determines the assertion status for classes initialized in the future that belong to the named package or any of its "subpackages".
The assertion status can be set for a named top-level class and any nested classes contained therein. This setting takes precedence over the class loader's default assertion status, and over any applicable per-package default. If the named class is not a top-level class, the change of status will have no effect on the actual assertion status of any class.
Which of the following statements is true?
Your Answer : (Not Answered)
Correct Answer : A
Option A is correct because it is sometimes advisable to thrown an assertion error even if assertions have been disabled.
Option B is incorrect because it is considered appropriate to check argument values in private methods using assertions.
Option C is incorrect; finally is never bypassed.
Option D is incorrect because AssertionErrors should never be handled.
What will be the output of the program?
public class RTExcept
{
public static void throwit ()
{
System.out.print("throwit ");
throw new RuntimeException();
}
public static void main(String [] args)
{
try
{
System.out.print("hello ");
throwit();
}
catch (Exception re )
{
System.out.print("caught ");
}
finally
{
System.out.print("finally ");
}
System.out.println("after ");
}
}
Your Answer : (Not Answered)
Correct Answer : D
The main() method properly catches and handles the RuntimeException in the catch block, finally runs (as it always does), and then the code returns to normal.
A, B and C are incorrect based on the program logic described above. Remember that properly handled exceptions do not cause the program to stop executing.
What will be the output of the program?
class SC2
{
public static void main(String [] args)
{
SC2 s = new SC2();
s.start();
}
void start()
{
int a = 3;
int b = 4;
System.out.print(" " + 7 + 2 + " ");
System.out.print(a + b);
System.out.print(" " + a + b + " ");
System.out.print(foo() + a + b + " ");
System.out.println(a + b + foo());
}
String foo()
{
return "foo";
}
}
Your Answer : (Not Answered)
Correct Answer : D
Because all of these expressions use the + operator, there is no precedence to worry about and all of the expressions will be evaluated from left to right. If either operand being evaluated is a String, the + operator will concatenate the two operands; if both operands are numeric, the + operator will add the two operands.
What will be the output of the program?
public class TestDogs
{
public static void main(String [] args)
{
Dog [][] theDogs = new Dog[3][];
System.out.println(theDogs[2][0].toString());
}
}
class Dog { }
Your Answer : (Not Answered)
Correct Answer : D
The second dimension of the array referenced by theDogs has not been initialized. Attempting to access an uninitialized object element (System.out.println(theDogs[2][0].toString());) raises a NullPointerException.
Which three are legal array declarations?
1.int [] myScores [];
2.char [] myChars;
3.int [6] myScores;
4.Dog myDogs [];
5.Dog myDogs [7];
Your Answer : (Not Answered)
Correct Answer : A
(1), (2), and (4) are legal array declarations. With an array declaration, you can place the brackets to the right or left of the identifier. Option A looks strange, but it's perfectly legal to split the brackets in a multidimensional array, and place them on both sides of the identifier. Although coding this way would only annoy your fellow programmers, for the exam, you need to know it's legal.
(3) and (5) are wrong because you can't declare an array with a size. The size is only needed when the array is actually instantiated (and the JVM needs to know how much space to allocate for the array, based on the type of array and the size).
Which one of these lists contains only Java programming language keywords?
Your Answer : (Not Answered)
Correct Answer : B
All the words in option B are among the 49 Java keywords. Although goto reserved as a keyword in Java, goto is not used and has no function.
Option A is wrong because the keyword for the primitive int starts with a lowercase i.
Option C is wrong because "virtual" is a keyword in C++, but not Java.
Option D is wrong because "constant" is not a keyword. Constants in Java are marked static and final.
Option E is wrong because "include" is a keyword in C, but not in Java.
Which four options describe the correct default values for array elements of the types indicated?
1.int -> 0
2.String -> "null"
3.Dog -> null
4.char -> '\u0000'
5.float -> 0.0f
6.boolean -> true
Your Answer : (Not Answered)
Correct Answer : B
(1), (3), (4), (5) are the correct statements.
(2) is wrong because the default value for a String (and any other object reference) is null, with no quotes.
(6) is wrong because the default value for boolean elements is false.
Total number of questions : 20
Number of answered questions : 0
Number of unanswered questions : 20
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