单项选择题
public interface A {
String DEFAULT_GREETING = “Hello World”;
public void method1();
}
A programmer wants to create an interface called B that has A as its parent. Which interface declaration is correct?()
A. public interface B extends A {}
B. public interface B implements A {}
C. public interface B instanceOf A {}
D. public interface B inheritsFrom A {}
相关考题
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多项选择题
package sun.scjp; public enum Color { RED, GREEN, BLUE } package sun.beta; // insert code here public class Beta { Color g = GREEN; public static void main( String[] argv) { System.out.println( GREEN); } } The class Beta and the enum Color are in different packages. Which two code fragments, inserted individually at line 2 of the Beta declaration, will allow this code to compile?()
A. import sun.scjp.Color.*;
B. import static sun.scjp.Color.*;
C. import sun.scjp.Color; import static sun.scjp.Color.*;
D. import sun.scjp.*; import static sun.scjp.Color.*;
E. import sun.scjp.Color; import static sun.scjp.Color.GREEN; -
多项选择题
10. interface Foo { 11. int bar(); 12. } 13. 14. public class Beta { 15. 16. class A implements Foo { 17. public int bar() { return 1; } 18. } 19. 20. public int fubar( Foo foo) { return foo.bar(); } 21. 22. public void testFoo() { 23. 24. class A implements Foo { 25. public int bar() { return 2; } 26. } 27. 28. System.out.println( fubar( new A())); 29. } 30. 31. public static void main( String[] argv) { 32. new Beta().testFoo(); 33. } 34. } Which three statements are true?()
A. Compilation fails.
B. The code compiles and the output is 2.
C. If lines 16, 17 and 18 were removed, compilation would fail.
D. If lines 24, 25 and 26 were removed, compilation would fail.
E. If lines 16, 17 and 18 were removed, the code would compile and the output would be 2.
F. If lines 24, 25 and 26 were removed, the code would compile and the output would be 1. -
单项选择题
10. interface Foo { int bar(); } 11. public class Sprite { 12. public int fubar( Foo foo) { return foo.bar(); } 13. public void testFoo() { 14. fubar( 15. // insert code here 16.); 17. } 18. } Which code, inserted at line 15, allows the class Sprite to compile?()
A. Foo { public int bar() { return 1; } }
B. new Foo { public int bar() { return 1; } }
C. newFoo() { public int bar(){return 1; } }
D. new class Foo { public int bar() { return 1; } }
