单项选择题
A. 420 is the output.
B. An exception is thrown at runtime.
C. All constructors must be declared public.
D. Constructors CANNOT use the private modifier.
E. Constructors CANNOT use the protected modifier.
多项选择题 interface A { public int getValue() } class B implements A { public int getValue() { return 1; } } class C extends B { // insert code here } Which three code fragments, inserted individually at line 15, make use of polymorphism?()
单项选择题 1. interface A { public void aMethod(); } 2. interface B { public void bMethod(); } 3. interface C extends A,B { public void cMethod(); } 4. class D implements B { 5. public void bMethod() { } 6. } 7. class E extends D implements C { 8. public void aMethod() { } 9. public void bMethod() { } 10. public void cMethod() { } 11. } What is the result?()
单项选择题 1. class SuperClass { 2. public a geta() { 3. return new a(); 4. } 5. } 6. class SubClass extends SuperClass { 7. public b geta() { 8. return new b(); 9. } 10. } Which is true?()