Answer Posted / chitij mehrotra

1 A class may inplement several interfaces. A class may
extend only one abstract class.
2 An interface can have only abstract methods. An abstract
class can have both abstract methods and concrete methods.
At one abstract method in the abstract class.
3 Interfaces cannot have constructors. Abstract class can
have constructors.
4 Only static final variables are allowed to be decelared.
Both static and instance variables are allowed.
5 All decelared methods are implicitly public. Can have any
kind of methods.
6 We should initialize variables in an interface. Not
necessary to initialize variables in an abstract class.
7 In the case of interface you can make any class in the
hierarchy. In the case of abstract class you know the class
hierarchy in advance.
8 An interface implementation may be added to any existing
third party class. A third party class must be rewritten to
extend only from the abstract class.
9 Interfaces can be implemented by classes that are not
related to one another Abstract classes are used only when
there is a “is-a” type of relationship between the classes.

Can list have duplicates in java?

870

---

Which java ide is used the most?

955

---

Can you add null to a list java?

1008

---

Do we need to manually write Copy Constructor?

986

---

What do you understand by weak reference?

964

---

Can we declare main () method as non static?

932

---

What is the meaning of immutable regarding string?

919

---

what is use of functional interface in java 8?

983

---

what are abstract functions?

979

---

how can i use a nonsynchronized hashtable?

2535

---

What are thread safe functions?

904

---

What is the meaning of I ++ in java?

1117

---

What is binary search in java?

950

---

What is variable and constant explain with example?

1035

---

What is difference overloading and overriding?

1095

---