JAVA Interfaces and Abstract Classes Which of the following statements regarding abstract classes are true? All of these A subclass can override a concrete method in a superclass to declare it abstract. A subclass of a non-abstract superclass can be abstract. An abstract class can be used as a data type. An abstract class can be extended. All of these A subclass can override a concrete method in a superclass to declare it abstract. A subclass of a non-abstract superclass can be abstract. An abstract class can be used as a data type. An abstract class can be extended. ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes interface Test{ int p = 10; //line 1 public int q = 20; //line 2 public static int r = 30; //line 3 public static final int s = 40; //line 4}Which of the above line will give compilation error? 2 None of these 4 3 1 2 None of these 4 3 1 ANSWER DOWNLOAD EXAMIANS APP
JAVA Interfaces and Abstract Classes Given the following piece of code:public interface Guard{ void doYourJob();}abstract public class Dog implements Guard{ }which of the following statements is correct? This code will not compile, because in the declaration of class Dog we must use the keyword extends instead of implements. This code will compile without any errors. This code will not compile, because class Dog must implement method doYourJob() from interface Guard. This code will not compile, because method doYourJob() in interface Guard must be defined abstract. This code will not compile, because in the declaration of class Dog we must use the keyword extends instead of implements. This code will compile without any errors. This code will not compile, because class Dog must implement method doYourJob() from interface Guard. This code will not compile, because method doYourJob() in interface Guard must be defined abstract. 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(); 2 and 3 1 and 2 3 and 4 2 and 4 1 and 3 2 and 3 1 and 2 3 and 4 2 and 4 1 and 3 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); }} Compilation error due to line 2 Runtime error Successful run and print 37 Compilation error due to line 1 None of these Compilation error due to line 2 Runtime error Successful run and print 37 Compilation error due to line 1 None of these 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()); }} Compilation fails due to an error on lines 2 test-name Compilation succeed but Runtime Exception Compilation fails due to an error on lines 1 None of these Compilation fails due to an error on lines 2 test-name Compilation succeed but Runtime Exception Compilation fails due to an error on lines 1 None of these ANSWER DOWNLOAD EXAMIANS APP
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