Question

NOTE: in mathematics, the square root of a negative number is not real; in Java therefore, passing such a value to the square root function returns a value known as NaN (not-a-number). Given a double variable named areaOfSquare write the necessary code to read in a value, the area of some square, into areaOfSquare and print out the length of the side of that square. HOWEVER: if any value read in is not valid input, just print the message "INVALID". ASSUME the availability of a variable, stdin, that references a Scanner object associated with standard input.

Answer 1

Answer:

// program in java.

import java.util.*;

// class definition

class Main

{// main method of the class

public static void main (String[] args) throws java.lang.Exception

{

   try{

    // object to read input

Scanner scr=new Scanner(System.in);

System.out.print("Enter area of square: ");

// read the area of square  

double areaOfSquare=scr.nextDouble();

// if area is negative

if(areaOfSquare<0)

{

// print Invalid

System.out.println("INVALID");

}

// else find side of the square and print it.

else

System.out.println("The side of the square is: "+Math.sqrt(areaOfSquare));

     

   }catch(Exception ex){

       return;}

}

}

Explanation:

Read the area of square from user and assign it to variable "areaOfSquare". If the area entered by user is negative then print "INVALID" otherwise find the  side of the square with Math.sqrt() function and print it.

Output:

Enter area of square: -4                                                                                                  

INVALID

Enter area of square: 25                                                                                                  

The side of the square is: 5.0