新华信国际信息咨询JAVA工程师笔试题和面试题答案(四)
1.package packageX.packageY;
2.
3.public class SubclassY extends SuperclassX
4.{
5.SuperclassX objX = new SubclassY();
6.SubclassY objY = new SubclassY();
7.void subclassMethodY()
8.{
9.objY.superclassMethodX();
10.int i;
11.i = objY.superclassVarX;
12.}
13.}
Choices:
What will be the result of executing the following code?
// Filename; SuperclassX.java
package packageX;
public class SuperclassX
{
protected void superclassMethodX()
{
}
int superclassVarX;
}
// Filename SubclassY.java
1.package packageX.packageY;
2.
3.public class SubclassY extends SuperclassX
4.{
5.SuperclassX objX = new SubclassY();
6.SubclassY objY = new SubclassY();
7.void subclassMethodY()
8.{
9.objY.superclassMethodX();
10.int i;
11.i = objY.superclassVarX;
12.}
13.}
Choices:
A.Compilation error at line 5
B.Compilation error at line 9
C.Runtime exception at line 11
D.None of these
12:Which statement about listener is true?
A.Most component allow multiple listeners to be added.
B.If multiple listener be add to a single component, the event only affected one listener.
