class BaseClass{
private float x= 1.0f;
protected void setVar (float f) {x = f;}
}
class SubClass exyends BaseClass {
private float x = 2.0f;
//insert code here 8. }
Which two are valid examples of method overriding?()
A. Void setVar(float f) {x = f;}
B. Public void setVar(int f) {x = f;}
C. Public void setVar(float f) {x = f;}
D. Public double setVar(float f) {x = f;}
E. Public final void setVar(float f) {x = f;}
F. Protected float setVar() {x=3.0f; return 3.0f; }
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class A {
public int getNumber(int a) {
return a + 1;
}
}
class B extends A {
public int getNumber (int a) {
return a + 2
}
public static void main (String args) {
A a = new B();
System.out.printIn(a.getNumber(0));
}
}
What is the result? ()
A. Compilation succeeds and 1 is printed.
B. Compilation succeeds and 2 is printed.
C. An error at line 8 causes compilation to fail.
D. An error at line 13 causes compilation to fail.
E. An error at line 14 causes compilation to fail.
import java.awt.*;
public class Test extends Frame {
public Test() {
add(new Label(“Hello”) );
add(new TextField(“Hello”) );
add(new Button(“Hello”) );
pack();
show();
}
public static void main(String args) {
new Test ();
}
}
What is the result? ()
A. The code will not compile.
B. A Window will appear containing only a Button.
C. An IllegalArgumentException is thrown at line 6.
D. A Window button will appear but will not contain the Label, TextField, or Button.
E. A Window will appear containing a Label at the top, a TextField below the Label, and a Button below the TextField.
F. A Window will appear containing a Label on the left, a TextField to the right of the Label, and a button to the right of the TextField.
A. Public class getClass()
B. Public Object getSource()
C. Public Component getSource()
D. Public Component getTarget()
E. Public Component getComponent()
F. Public Component getTargetComponent()
A. A flow layout can be used to position a component that should resize horizontally when the container is resized.
B. A grid layout can be used to position a component tat should maintain a constant size even when the container is resized.
C. A border layout can be used to position component that should maintain a constant size even when the container is resized.
D. The grid bag layout can be used to give a grid-like layout which differs from the normal grid in that individual rows and columns can have unique sizes.
E. If two components are placed in the same column of a grid bag layout, and one component resizes horizontally, then the other component must resize horizontally.
A. Int foo = (int) Math.max(bar);
B. Int foo = (int) Math.min(bar);
C. Int foo = (int) Math.abs(bar);
D. Int foo = (int) Math.ceil(bar);
E. Int foo = (int) Math.floor(bar);
F. Int foo = (int) Math.round(bar);
A. Run();
B. Start();
C. Execute();
D. Run(Runnable r);
E. Start(Runnable r);
F. Execute(Thread t);
public class SyncTest{
public static void main(String args) {
final StringBuffer s1= new StringBuffer();
final StringBuffer s2= new StringBuffer();
new Thread () {
public void run() {
synchronized(s1) {
s2.append(“A”);
synchronized(s2) {
s2.append(“B”);
System.out.print(s1);
System.out.print(s2);
}
}
}
}.start();
new Thread() {
public void run() {
synchronized(s2) {
s2.append(“C”);
synchronized(s1) {
s1.append(“D”);
System.out.print(s2);
System.out.print(s1);
}
}
}
}.start();
}
}
Which two statements are true? ()
A. The program prints “ABBCAD”
B. The program prints “CDDACB”
C. The program prints “ADCBADBC”
D. The output is a non-deterministic point because of a possible deadlock condition.
E. The output is dependent on the threading model of the system the program is running on.
A. Existing from a synchronized block.
B. Calling the wait method on an object.
C. Calling notify method on an object.
D. Calling read method on an InputStream object.
E. Calling the SetPriority method on a Thread object.
public class X implements Runnable (
private int x;
private int y;
public static void main(String args) (
X that = new X();
(new Thread(that)) . start( );
(new Thread(that)) . start( );
)
public synchronized void run( ) (
for (;;) (
x++;
y++;
System.out.printIn(“x = “ + x + “, y = “ + y);
)
)
)
What is the result?()
A. An error at line 11 causes compilation to fail.
B. Errors at lines 7 and 8 cause compilation to fail.
C. The program prints pairs of values for x and y that might not always be the same on the same line (for example, “x=2, y=1”)
D. The program prints pairs of values for x and y that are always the same on the same line (forexample, “x=1, y=1”. In addition, each value appears twice (for example, “x=1, y=1” followed by “x=1, y=1”)
E. The program prints pairs of values for x and y that are always the same on the same line (for example, “x=1, y=1”. In addition, each value appears twice (for example, “x=1, y=1” followed by “x=2s, y=2”)
最新试题
A programmer is developing a class Key, that will be used as a key in a standard java.util.HashMap. Which two methods should be overridden to assure that Key works correctly as a key?()
Which three changes should be made to adapt this class to be used safely by multiple threads?()
Which two are possible results?()
Which two statements are true?()
Which statement is true?()
What is the result?()
What is the result?()
Which two changes, taken together, would guarantee the output: 1, 2, 3, 4, 5?()
Which statement is true?()
What is the result?()