Java - Declarations and Access Control
Java - Declarations and Access Control
1. You want subclasses in any package to have access to members of a superclass. Which is the most restrictive access that accomplishes this objective?
- public
- private
- protected
- transient
2. public class Outer
{
public void someOuterMethod()
{
//Line 5
}
public class Inner { }
public static void main(String[] argv)
{
Outer ot = new Outer();
//Line 10
}
}
Which of the following code fragments inserted, will allow to compile?
{
public void someOuterMethod()
{
//Line 5
}
public class Inner { }
public static void main(String[] argv)
{
Outer ot = new Outer();
//Line 10
}
}
Which of the following code fragments inserted, will allow to compile?
- new Inner(); //At line 5
- new Inner(); //At line 10
- new ot.Inner(); //At line 10
- new Outer.Inner(); //At line 10
3. interface Base
{
boolean m1 ();
byte m2(short s);
}
which two code fragments will compile?
1. interface Base2 implements Base {}
2. abstract class Class2 extends Base
{ public boolean m1(){ return true; }}
3. abstract class Class2 implements Base {}
4. abstract class Class2 implements Base
{ public boolean m1(){ return (7 > 4); }}
5 .abstract class Class2 implements Base
{ protected boolean m1(){ return (5 > 7) }}
{
boolean m1 ();
byte m2(short s);
}
which two code fragments will compile?
1. interface Base2 implements Base {}
2. abstract class Class2 extends Base
{ public boolean m1(){ return true; }}
3. abstract class Class2 implements Base {}
4. abstract class Class2 implements Base
{ public boolean m1(){ return (7 > 4); }}
5 .abstract class Class2 implements Base
{ protected boolean m1(){ return (5 > 7) }}
- 1 and 2
- 2 and 3
- 3 and 4
- 1 and 5
4. Which three form part of correct array declarations?
1. public int a [ ]
2. static int [ ] a
3. public [ ] int a
4. private int a [3]
5.private int [3] a [ ]
6. public final int [ ] a
1. public int a [ ]
2. static int [ ] a
3. public [ ] int a
4. private int a [3]
5.private int [3] a [ ]
6. public final int [ ] a
- 1, 3, 4
- 2, 4, 5
- 1, 2, 6
- 2, 5, 6
5. public class Test { }
What is the prototype of the default constructor?
What is the prototype of the default constructor?
- Test( )
- Test(void)
- public Test( )
- public Test(void)
6. What is the most restrictive access modifier that will allow members of one class to have access to members of another class in the same package?
- public
- abstract
- protected
- synchronized
7. Which of the following is/are legal method declarations?
protected abstract void m1();
static final void m1(){}
synchronized public final void m1() {}
private native void m1();
protected abstract void m1();
static final void m1(){}
synchronized public final void m1() {}
private native void m1();
- 1 and 3
- 2 and 4
- 1 only
- All of them are legal declarations.
8. Which cause a compiler error?
- int[ ] scores = {3, 5, 7};
- int [ ][ ] scores = {2,7,6}, {9,3,45};
- String cats[ ] = {"Fluffy", "Spot", "Zeus"};
- boolean results[ ] = new boolean [] {true, false, true};
9. Which three are valid method signatures in an interface?
private int getArea();
public float getVol(float x);
public void main(String [] args);
public static void main(String [] args);
boolean setFlag(Boolean [] test);
private int getArea();
public float getVol(float x);
public void main(String [] args);
public static void main(String [] args);
boolean setFlag(Boolean [] test);
- 1 and 2
- 2, 3 and 5
- 3, 4, and 5
- 2 and 4
10. 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?
- public
- private
- protected
- default access