1) Base of hexadecimal number system? Answer : 16 2) Universal gate in digital logic? Answer : NAND 3) Memory type that is non-volatile? Answer : ROM 4) Basic building block of digital circuits? Answer : Gate 5) Device used for data storage in sequential circuits? Answer : Flip-flop 6) Architecture with shared memory for instructions and data? Answer : von Neumann 7) The smallest unit of data in computing? Answer : Bit 8) Unit that performs arithmetic operations in a CPU? Answer : ALU 9) Memory faster than main memory but smaller in size? Answer : Cache 10) System cycle that includes fetch, decode, and execute? Answer : Instruction 11) Type of circuit where output depends on present input only? Answer : Combinational 12) The binary equivalent of decimal 10? Answer : 1010 13) Memory used for high-speed temporary storage in a CPU? Answer : Register 14) Method of representing negative numbers in binary? Answer : Two's complement 15) Gate that inverts its input signal? Answer : NOT 16)...
Q) What is Inheritance ?
Inheritance is one of the key features of object oriented programming. It is the mechanism in java in which one class inherits the properties (methods and fields) of another class.
The class which inherits the properties of other is known as subclass and the class whose properties are inherited is known as superclass.
extends is the keyword used to inherit the properties of a class. Following is the syntax of extends keyword.
Syntax:
class Super {
..........
..........
}
class Sub extends Super {
..........
..........
}
Q) Can an interface implement or extend another interface ?
Interface can't implement another interface, since interfaces can't have method implementations. An interface can extend another interface.
Q) What is Marker interface ?
A Marker interface is an empty interface without any method but used to force some functionality in implementing classes by java. Some of the well known marker interfaces are Serializable and Cloneable.
Q) What is multiple inheritance? Is it supported by Java?
Multiple inheritance is a feature of object oriented concept, where a class can inherit properties of more than one parent class. The problem occurs when there exist methods with same signature in both the super classes. On calling the method, the compiler cannot determine which class method to be called. Java doesn't allow multiple inheritance to avoid the ambiguity caused by it. One of the example of such problem is the diamond problem that occurs in multiple inheritance.
Consider the below java code. It produce compile time error.
// First Parent class
class Parent1
{
void fun()
{
System.out.println("Parent1");
}
}
// Second Parent class
class Parent2
{
void fun()
{
System.out.println("Parent2");
}
}
// Error : Test is inheriting from multiple class
class Test extends Parent1,Parent2
{
public static void main(String args [])
{
Test t = new Test();
// Calling the method fun() using Test object
t.fun();
}
}