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Is it necessary that all the abstract methods must be defined from an abstract class?

Is it necessary that all the abstract methods must be defined from an abstract class? Correct Answer Yes, always

That is the rule of programming language that each function declared, must have some definition. There can’t be some abstract method that remains undefined. Even if it’s there, it would result in compile time error.

Related Questions

Which of the following is/are true for an abstract class?
1. A class is declared abstract by prefacing the definition with the word abstract.
2. A class is declare abstract by using the keyword implements.
3. It is a class that really isn’t supposed to ever be instantiated but instead serves as a base class.
4. Attempting to instantiate an abstract class results in an error.
Which of the following is/are true for an abstract class? i) Abstract classes in PHP are declared with the help of abstract keyword. ii) A class is declare abstract by using the keyword implements. iii) It is a class that really isn’t supposed to ever be instantiated but instead serves as a base class. iv) Attempting to instantiate an abstract class results in an error.
Which of the following statements regarding static methods are correct?
1. Static methods are difficult to maintain, because you can not change their implementation.
2. Static methods can be called using an object reference to an object of the class in which this method is defined.
3. Static methods are always public, because they are defined at class-level.
4. Static methods do not have direct access to non-static methods which are defined inside the same class. 
interface Base{ boolean m1 (); byte m2(short s);}

which two code fragments will compile?
1. interface Base2 implements Base {}2. abstract class Class2 extends Base { public boolean m1(){ return true; }}3. abstract class Class2 implements Base {}4. abstract class Class2 implements Base { public boolean m1(){ return (7 > 4); }}5. abstract class Class2 implements Base { protected boolean m1(){ return (5 > 7) }}
Which two classes use the Shape class correctly?
A. public class Circle implements Shape { private int radius; }B. public abstract class Circle extends Shape { private int radius; }C. public class Circle extends Shape { private int radius; public void draw(); }D. public abstract class Circle implements Shape { private int radius; public void draw(); }E. public class Circle extends Shape { private int radius; public void draw() { /* code here */ } }F. public abstract class Circle implements Shape { private int radius; public void draw() { /* code here */ } }
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 {}
There are five classes class 1, class 2, class 3, class 4 and class 5 in a school. They are one above the other. Class 1 is at the bottom, then class 2 above it and so on. Five videos M1, M2, M3, M4 and M5 are displayed in these given classes. Only one video is displayed in a particular class. Each video is displayed only one time. Video M5 is displayed at an even numbered class. Video M2 is displayed at class 1. Video M1 is displayed at the class just below M5. Video M4 is not displayed at even numbered class. Which of the following statement is not correct?
h,J,K,L,M,N and O are the only legislators eligible to vote on Bills 1,2 and 3, each of which will be passed if at least four legislators eligible vote in favor of it. each legislator must vote on all three bills; on abstentions are possible. The following is known : *H must vote against all three bills; each of the other legislators must vote in favor of at least one bill and against at lest one bill. *j must vote against Bills 1. *O Must vote against Bills 2 and 3. * L must the same way that K dose on all three bills.*N must vote the same way that O dose on all three bills. which of the following must vote in favor of Bill 1 ?
h,J,K,L,M,N and O are the only legislators eligible to vote on Bills 1,2 and 3, each of which will be passed if at least four legislators eligible vote in favor of it. each legislator must vote on all three bills; on abstentions are possible. The following is known : *H must vote against all three bills; each of the other legislators must vote in favor of at least one bill and against at lest one bill. *j must vote against Bills 1. *O Must vote against Bills 2 and 3. * L must the same way that K dose on all three bills.*N must vote the same way that O dose on all three bills. If any bill is to be passed,which of the following must be among the legislators who vote in favor of it?
Abstract class A has 4 virtual functions. Abstract class B defines only 2 of those member functions as it extends class A. Class C extends class B and implements the other two member functions of class A. Choose the correct option below.