19： ? ? 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();
14. System.out.printIn(a.getNumber(0));
15. ? ?}
16. } ?
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.
Answer：B。記住一句話，成員變量（編譯時）看左邊，方法（運行時）看右邊。