Page 149 - ComputerScience_Class_11

Ans. Rules for naming a variable are:
• A variable name should start with a letter.
• A variable name may contain any number of letters, digits and underscores.
• The name should have a meaning related to the program.
• There should not be any space between the letters in the name of the variable.
• Variable names cannot be reserved words.
8. What is the difference between Pure Arithmetic Expression and Mixed Arithmetic Expression?
Ans. The difference between them is as follows:
Pure Arithmetic Expression Mixed Arithmetic Expression
When the variables and constants in an expression are of When the variables and constants in an expression are of
the same data types, then the expression is known as a pure different data types, then the expression is known as a mixed
arithmetic expression. arithmetic expression.
For example: For example:
double dia=34,r,pi=3.142,ar_circle; int a=5;
r=34/2.0; char ch='a';
ar_circle=pi*r*r; double sum = a+ch;
System.out.println("Area of circle "+ar_ System.out.println("Result : " + sum);
circle); //Output: Result : 102.0
//Output : Area of circle 908.038
9. What are operators in Java? Write a program to demonstrate the use of arithmetic operators by performing basic mathematical
operations.
Ans. Operators are the special symbols that signify the compiler to perform some specific mathematical or non-mathematical
operations on one or more operands.
A program using arithmetic operators:
public class ArithmeticExample {
public static void main(String[] args) {
int a = 10;
int b = 5;

// Addition
int sum = a + b;
System.out.println("Sum: " + sum);

// Subtraction
int difference = a - b;
System.out.println("Difference: " + difference);

// Multiplication
int product = a * b;
System.out.println("Product: " + product);

// Division
int quotient = a / b;
System.out.println("Quotient: " + quotient);
}

Primitive Values, Wrapper Classes, Types and Casting 147