Number Calculations

//   Write a program that outputs the results of the following evaluations based on the number entered by the user.
//  (i)     Natural logarithm of the number
//  (ii)    Absolute value of the number
//  (iii)   Square root of the number
//  (iv)    Random number between 0 and 1

// VARIABLE DESCRIPTION :
//NUM= NUMBER INPUTTED BY THE USER
//ANS= THE ANSWER OF EACH OPERATION


import java.io.*;
class NUMBER_CALCULATIONS
{
    private static double num,ans;
  
 public static void main(String args[])throws IOException
    {
        System.out.println(".............................................................................................................................");
        System.out.println("                                       .........................................................");
        System.out.println("                                       . ENTER A  NUMBER FOR PERFORMING THE FOLLOWING ACTIONS: .");
        System.out.println("                                       . NATURAL LOGORITH OF THAT NUMBER                       .");
        System.out.println("                                       . ABSOLUTE VALUE OF THAT NUMBER                         .");
        System.out.println("                                       . SQUARE ROOT OF THAT NUMBER                            .");
        System.out.println("                                       . DISPLAYS A RANDOM NUMBER GENERATED BY THE SYSTEM      .");
        System.out.println("                                       ........................................................");
        System.out.println("");
        System.out.println(".............................................................................................................................");
        System.out.println("");
        
        InputStreamReader reader=new InputStreamReader(System.in);
        BufferedReader input=new BufferedReader(reader);
        System.out.println("ENTER A NUMBER FOR PERFORMING THE CALCULATIONS GIVEN ABOVE");
        System.out.print("USER INPUT :");
        try
        {
            num=Double.parseDouble(input.readLine());
        }
        catch(Exception b)
        {
            System.out.println("");
            System.out.println("\t\tERROR FOUND : YOU HAVE TO ENTER ONLY INTEGERS PLEASE RERUN THE PROGRAM");
            System.exit(0);
        }
        int temp_choice=1;
        switch(temp_choice)
        {
            case 1:
            {
                System.out.println(".............................................................................................................................");
                System.out.println("NATURAL LOGORITH :");
                System.out.println("");
                ans=Math.log(num);
                System.out.println("THE NATURAL LOGORITH OF "+num+" IS "+ans);
                System.out.println("");
               
                System.out.println(".............................................................................................................................");
            }
            case 2:
            {
                System.out.println("ABSOLUTE VALUE :");
                System.out.println("");
                ans=Math.abs(num);
                System.out.println("THE ABSOLUTE VALUE OF "+num+" IS "+ans);
                System.out.println("");
               
                System.out.println(".............................................................................................................................");
            }
            case 3:
            {
                System.out.println("SQUARE ROOT :");
                System.out.println("");
                ans=Math.sqrt(num);
                System.out.println("THE SQUARE ROOT OF "+num+" IS "+ans);
                System.out.println("");
               
                System.out.println(".............................................................................................................................");
            }
            case 4:
            {
                System.out.println("GENERATES A RANDOM NUMBER :");
                System.out.println("");
                ans=Math.random();
                System.out.println("THE RANDOM NUMBER GENERATED IS "+ans);
                System.out.println("");
              
                System.out.println(".............................................................................................................................");
            }
        }
    }
   
}
               
                OUTPUT 1:


.............................................................................................................................

                                       .........................................................

                                       . ENTER A  NUMBER FOR PERFORMING THE FOLLOWING ACTIONS: .

                                       . NATURAL LOGORITH OF THAT NUMBER                       .

                                       . ABSOLUTE VALUE OF THAT NUMBER                         .

                                       . SQUARE ROOT OF THAT NUMBER                            .

                                       . DISPLAYS A RANDOM NUMBER GENERATED BY THE SYSTEM      .

                                       ........................................................



.............................................................................................................................



ENTER A NUMBER FOR PERFORMING THE CALCULATIONS GIVEN ABOVE

USER INPUT :5
.............................................................................................................................

NATURAL LOGORITH :



THE NATURAL LOGORITH OF 5.0 IS 1.6094379124341003



.............................................................................................................................

ABSOLUTE VALUE :



THE ABSOLUTE VALUE OF 5.0 IS 5.0



.............................................................................................................................

SQUARE ROOT :



THE SQUARE ROOT OF 5.0 IS 2.23606797749979



.............................................................................................................................

GENERATES A RANDOM NUMBER :



THE RANDOM NUMBER GENERATED IS 0.8859643474919592



.............................................................................................................................

                   OUTPUT 2:
.............................................................................................................................

                                       .........................................................

                                       . ENTER A  NUMBER FOR PERFORMING THE FOLLOWING ACTIONS: .

                                       . NATURAL LOGORITH OF THAT NUMBER                       .

                                       . ABSOLUTE VALUE OF THAT NUMBER                         .

                                       . SQUARE ROOT OF THAT NUMBER                            .

                                       . DISPLAYS A RANDOM NUMBER GENERATED BY THE SYSTEM      .

                                       ........................................................



.............................................................................................................................



ENTER A NUMBER FOR PERFORMING THE CALCULATIONS GIVEN ABOVE

USER INPUT :h


        ERROR FOUND : YOU HAVE TO ENTER ONLY INTEGERS PLEASE RERUN THE PROGRAM