ICSE Class X Computer Applications ( Java ) Solved Model Question Papers 01

Question 1.

a.       Define Encapsulation.

Ans: The wrapping of data and function together into a single unit is called Encapsulation.

b.      Name any two OOP’s principles

Ans: Inheritance and Polymorphism

c.       Define Object with an example.

Ans:  Object: An instance of a class called Object. The table is an instance of class Furniture.

Class: Blue print of an object is called Class. Example, mango, apple, and orange are members of the class fruit.

d.      What is wrapper class? Give example.

e.      A wrapper class is a class which wraps a primitive data type. Example Double, Float, Integer

Question 2.

a.       What is a class variable?

Ans: Instance variables having the keyword static before it is a class variable. For every object, there is just one copy of the variable made.

b.      What is the significance of import java.io.* in your program?

Ans: The line imports all the classes of the java.io package into the current program.

c.       State the two kinds of data types.

Ans: The two kinds of data types in Java are primitive and reference data types.

d.      Define impure function.

Ans: Impure Function: A function that brings about a change in the argument that it receives. Its arguments will always be reference types. It may or may not return value. In other words, an impure function brings about a change in the state of the function. This change in state is called the side effect of calling an impure function.

Example:

Static void count(Number num) 

{

        num.counter=num.counter+1;

}

e.      What are comments? Name the different types.

Ans: Comments are statements which enhance the readability and understanding of the program. They are not part of the program.

The different types are: single line (//….), multiple line (/* … */) and documenting comment (/**….*/).