Question

Hello. I am using a Java program, which is console-baed.

Here is my question. Thank you.

1-1

Write a Java program, using appropriate methods and parameter passing, that obtains from the user the following items: a person’s age, the person’s gender (male or female), the person’s email address, and the person’s annual salary. The program should continue obtaining these details for as many people as the user wishes.

As the data is obtained from the user

• validate the age to ensure that the value lies in the range 20 to 30 inclusive; you may assume that the user will enter whole numbers only.

• validate the salary to ensure that it lies in the range 40000 to 150000 inclusive; you may assume that the user will enter whole numbers only.

• write the data to a text file named salaries.txt in the following format: age; gender; email address; salary

  Note: each line of data represents one person and each data value is separated by a semicolon (;). Hence the data in the file that you create would look similar to:

              22;male;brad#gmil.com;65000
              20;female;lucy#icloud.com;72000
              21;female;angela.Samson#yahoo.com.au;51000
              23;female;m_king#me.com;125000
  

(# = @)

• When the program terminates it should display to the screen how many of the people were male and how many were female that were written to the file.

1-2

0. A file named loanBalance.txt contains numeric values that represent the balance of home loans for customers of a bank. The loan balance for each customer is on a separate line within the file. Example data from the file might be similar to:

   65340.50
   43892.00
   38102.95
   89820.75
   106530.60
   

   Your Java program must

   • read the file into an appropriate array – you may assume that the file exists. The array should be sized to store 500 loan balances but keep in mind that the file may not contain 500 loan balances.

   • after reading the file into the array, calculate and display the average (mean) of the loan balances

     from the array.

   • after reading the file into the array, determine and display the largest loan balance from the array.

   • use appropriate methods and parameter passing.

Answer 1

//Solution 1

//Java code

import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws FileNotFoundException {
        int age;
        String gender;
        String email;
        int annualSalary;
        //Open file to write data
        PrintWriter writer = new PrintWriter("salaries.txt");
        Scanner input  = new Scanner(System.in);
        char choice=' ';
        int maleCounter=0,femaleCounter=0;
        do {
            System.out.print("Enter person's age: ");
            age = input.nextInt();
            /**
             * validate the age to ensure that the
             * value lies in the range 20 to 30
             */
            while (age<20 || age>30)
            {
                System.err.println("Please enter valid age (20 - 30).");
                System.out.print("Enter person's age: ");
                age = input.nextInt();
            }
            System.out.print("Enter person's gender: ");
            gender = input.next();
            if(gender.equalsIgnoreCase("male"))
                maleCounter++;
            else
                femaleCounter++;
            System.out.print("Enter person's emailId: ");
            email = input.next();
            System.out.print("Enter person's salary: ");
            annualSalary = input.nextInt();
            while (annualSalary<40000 || annualSalary>150000)
            {
                System.err.println("Please enter valid salary(40000 - 150000).");
                System.out.print("Enter person's salary: ");
                annualSalary = input.nextInt();
            }
            //write data to file
            writer.println(age+";"+gender+";"+email+";"+annualSalary);
            System.out.print("Do you want to continue (y/n): ");
            choice = input.next().toLowerCase().charAt(0);
        }while (choice=='y');
        //close the stream
        writer.close();
        System.out.println("\nNumber of females written to file: "+femaleCounter);
        System.out.println("Number of males written to file: "+maleCounter);
    }
}

//salaries.txt

Main.java * salaries.txt $2;male; brad#gmil.com; 65000 20; female; lucy#icloud.com;72000

//Output

"C:\Program Files\Java\jdk1.8.0_221\bin\java.exe" ... Enter person's age: 22 Enter person's gender: male Enter person's emailid: brad#gmil.com Enter person's salary: 65999 Do you want to continue (y/n): y Enter person's age: 29 Enter person's gender: female Enter person's emailid: Lucy#icloud.com Enter person's salary: 72998 Do you want to continue (y/n): n Number of females written to file: 1 Number of males written to file: 1 Process finished with exit code 6

//Solution 2

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class Loan {
    public static void main(String[] args)
    {
        /**
         *  The array should be sized to store 500 loan balances
         *  but keep in mind that the file may not contain 500
         *  loan balances.
         */
        double[] loans = new double[500];
        int counter =0;
        try {
            //open the file
            Scanner scanfile = new Scanner(new File("loanBalance.txt"));
            while (scanfile.hasNextDouble())
            {
                loans[counter]= scanfile.nextDouble();
                counter++;
            }
            //print stats
            System.out.println("Average of Loans: "+getAverage(loans,counter));
            System.out.println("Largest Loan: "+getLargestLoanBalance(loans,counter));


        }
        catch (FileNotFoundException e)
        {
            System.err.println("File not found.");
        }
    }
    private static double getAverage(double[] loans, int size)
    {
        double  sum=0,avg;
        for (int i = 0; i <size ; i++) {
            sum+=loans[i];

        }
        avg = sum/size;
        return avg;
    }
    private static double getLargestLoanBalance(double[] loans, int size)
    {
        double max = loans[0];
        for (int i = 0; i <size ; i++) {

            //find largest loan
            if(max<loans[i])
                max = loans[i];
        }
        return max;
    }
}

//Files

loanBalance.txt in.javax 65340.50 43892.00 38102.95 89820.75 106530.60

//Output

"C:\Program Files\Java\jdk1.8.0_221\bin\java.ex Average of Loans: 68737.36000000002 Largest Loan: 106530.6 Process finished with exit code o

//If you need any help regarding this solution .......... please leave a comment ......... thanks