Answer Posted / pankaj kumar

Yes,If A class have an abstract method the class must be declared as abstract, but if a class is declared as abstract
then,this is not mandatory that class hold any abstract method.

exa :
1. public Abstract class a{

// instance method;
}
///Above declaration is right

2. public class a{

// instance method;
// abstract method; //then you must declare this class as abstract.
}
///Above declaration is right

Is nan false?

931

---

Differentiate between array list and vector in java.

1076

---

A non-static inner class may have object instances that are associated with instances of the class’s outer class. A static inner class does not have any object instances.

980

---

What does system out println () do?

980

---

What are variable names?

927

---

What is a stringbuffer?

936

---

When can you say a graph to be a tree?

1043

---

What is exception in java?

1038

---

Can we use this () and super () in a method?

940

---

What is the symbol for line break?

1049

---

Define a package.

1025

---

What is foreach loop in java?

968

---

Give differences between Quicksort &Mergesort. When should these sorts be used andwhat is their running time in java?

1192

---

What is difference between this and super keyword?

949

---

From the two, which would be easier to write: synchronization code for ten threads or two threads?

1015

---