JAVA Interfaces and Abstract Classes In Java, declaring a class abstract is useful When default implementations of some methods are not desirable. When it makes sense to have objects of that class. When it doesn't make sense to have objects of that class. To prevent developers from further extending the class. To force developers to extend the class not to use its capabilities. When default implementations of some methods are not desirable. When it makes sense to have objects of that class. When it doesn't make sense to have objects of that class. To prevent developers from further extending the class. To force developers to extend the class not to use its capabilities. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which two of the following are legal declarations for abstract classes and interfaces?1. final abstract class Test {}2. public static interface Test {}3. final public class Test {}4. protected abstract class Test {}5. protected interface Test {}6. abstract public class Test {} 5 and 6 2 and 4 1 and 2 3 and 5 3 and 6 5 and 6 2 and 4 1 and 2 3 and 5 3 and 6 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Suppose A is an abstract class, B is a concrete subclass of A, and both A and B have a default constructor. Which of the following is correct?1. A a = new A();2. A a = new B();3. B b = new A();4. B b = new B(); 1 and 3 2 and 3 3 and 4 2 and 4 1 and 2 1 and 3 2 and 3 3 and 4 2 and 4 1 and 2 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Which of the following declares an abstract method in an abstract Java class? public abstract method(); public abstract void method(); public abstract void method() {} public void abstract Method(); public void method() {} public abstract method(); public abstract void method(); public abstract void method() {} public void abstract Method(); public void method() {} ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will be the output?1. public interface InfA{2. protected String getName();3. }public class Test implements InfA{ public String getName(){ return "test-name"; } public static void main (String[] args){ Test t = new Test(); System.out.println(t.getName()); }} None of these test-name Compilation succeed but Runtime Exception Compilation fails due to an error on lines 2 Compilation fails due to an error on lines 1 None of these test-name Compilation succeed but Runtime Exception Compilation fails due to an error on lines 2 Compilation fails due to an error on lines 1 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes What will happen after compiling this program code?abstract class MyClass{ //line 1 private int a, b; public void call(int a, int b){ this.a = a; this.b = b; System.out.print(a+b); }}public class Test{ public static void main(String args[]){ MyClass m = new MyClass(); //line 2 m.call(12,25); }} Successful run and print 37 Compilation error due to line 2 None of these Compilation error due to line 1 Runtime error Successful run and print 37 Compilation error due to line 2 None of these Compilation error due to line 1 Runtime error ANSWER DOWNLOAD EXAMIANS APP
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