单项选择题
现有:
interface Animal {
void eat () ;
}
//insert code here
public class HouseCat extends Feline {
public void eat() { }
}
和五个申明
abstract class Feline implements Animal { }
abstract class Feline implements Animal { void eat () ; }
abstract class Feline implements Animal { public void eat();}
abstract class Feline implements Animal { public void eat() {} }
abstract class Feline implements Animal { abstract public void eat();}
结果为:()
A.1
B.2
C.3
D.4
相关考题
-
单项选择题
现有: class Tree { private static String tree = "tree "; String getTree () { return tree; } } class Elm extends Tree { private static String tree = "elm "; public static void main (String [] args) { new Elm() .go (new Tree()) ; } } void go (Tree t) { String s = t.getTree () +Elm.tree + tree + (new Elm() .getTree ()) ; System.out.println (s) ;} 结果为:()
A. elm elm elm elm
B. tree elm elm elm
C. tree elm elm tree
D. tree elm tree elm -
单项选择题
现有两个文件: package X; public class X { public static void doX() {System.out.print ("doX"); } } 和: import x.X; class Find { publiC static void main (String [] args) { X myX=new X(); myX.doX(); X.doX(); x.X.aoX(): x.X myX2=new x.X(); myx2 .doX(); } } 结果为:()
A. Find类中第4行出现一个错误,编译失败。
B. Find类第5行出现一个错误,编译失败。
C. Find类第6行出现一个错误,编译失败。
D. doX doX doX doX -
单项选择题
现有: class Top { static int X=l; public Top() { x*=3; } } class Middle extends Top { public Middle() {x+=l; } public static void main(String [] args) { Middle m=new Middle(); System.out.println (x); } } 结果是什么?()
A. 2
B. 3
C. 4
D.编译失败
