Java Program Write a java program in which main prompts for

Java Program:

Write a java program in which main prompts for and reads in a double constant and then displays the square of the constant. If the user does not enter a double constant, your program should reprompt the user for a valid input. [Do not use hasNextDouble to determine if the inputs is invalid. Instead, catch the exception that nextDouble throws if the input is invalid.] Your program should use the prompt and error messages illustrated by the following sample session:

Enter non-negative double constant hello Not a double constant. Re-enter goodbye Not a double constant. Re-enter 4 Square of 4 = 16.0

Do not use hasNextDouble to determine if the inputs is invalid. Instead, catch the exception that nextDouble throws if the input is invalid.

Solution

import java.util.*;
public class DoubleSqr {

   public static void main(String[] args) throws java.util.InputMismatchException {
  
       // TODO Auto-generated method stub
      
       try
       {
       double n1, sqr;
       Scanner sc=new Scanner(System.in);
      
       System.out.println(\"Enter a number\");
       n1=sc.nextDouble();
       sqr=n1*n1;
       System.out.println(\"Squire of\"+n1+\"is\"+sqr);
       }
       catch(java.util.InputMismatchException E)
       {
           System.out.println(\" Invalid Input ==>\" +E);
       }

   }

}