How can I Calculate the maximum and minimum salary of the employees?

Question

import java.util.*;

class EmployeesDetails {
    System.out.println("Welcome Aboard!");
    Scanner emp = new Scanner(System.in);
    List<EmployeesDetails> employeesDetails = new ArrayList<>();
    Boolean empQuestion = true;

    while (empQuestion == true) {
        System.out.println("Do you want to enter the employee details? Yes or No");
        String inputString = emp.next();
        empQuestion = inputString.equalsIgnoreCase("Yes") ? true : false;

        if (empQuestion == false) {
            System.out.println("Come again Later!");
            break;
        }

        System.out.println("Enter the employee name: ");
        String empName = emp.next();

        System.out.println("Enter the employee ID");
        String empID = emp.next();

        System.out.println("Enter the employee Phone number");
        String empPhoneNumber = emp.next();

        System.out.println("Enter the employee Salary");
        Float empSalary = emp.nextFloat();

        EmployeesDetails employee = new EmployeesDetails(empName, empID, empPhoneNumber, empSalary);
        employeesDetails.add(employee);
        System.out.println(employeesDetails);
    }

    emp.close();
}

1. Hi everyone, So here I've written a program for adding the employee details.
2. I want to add the minimum and maximum wage for the employees, for example let's say if I have added 10 employees then I want to display the minimum salary of the employee who earns the least and display the salary of the employee who earns the highest.
3. My initial approach was to use Math.min() but then I realized that it is used for comparing between two values. Then my second approach was to Collections.min(); but I realized it's used the min value of the list.
4. Thank you and please go easy on me I've just started to learn coding.

Answer 1

The following demonstrates 4 possible solutions. Note the comments:

import java.util.*;

public class Main{

    public static void main(String[] args) {

        //Hardcoded data to make it more of an mre
        List<EmployeesDetails> employeesDetails = new ArrayList<>();
        employeesDetails.add(new EmployeesDetails("Sara", 1000f));
        employeesDetails.add(new EmployeesDetails("Deby", 1400f));
        employeesDetails.add(new EmployeesDetails("Dan", 1200f));
     
        //solution 1
        //Iterate over the collection and keep the employee with the highest (you can also keep the lowest)
        EmployeesDetails highestSalary = employeesDetails.get(0);
        for(EmployeesDetails e :employeesDetails ){
            if(e.getEmpSalary() > highestSalary.getEmpSalary()){
                highestSalary = e;
            }
        }

        //solution 2 contributed by Charlie Armstrong
        //Use Collections.max ( Collections.min )
        EmployeesDetails empD = Collections.max(employeesDetails, (e1, e2) -> Float.compare(e1.getEmpSalary(), e2.getEmpSalary()));
        System.out.println("employee with highest salary is "+empD);

        //solution 3
        //Use a stream, sort by salary find first to get the lowest
        //sort by salary in reverse and find first to get the highest
        Optional<EmployeesDetails> opEmpD = employeesDetails.stream().sorted((e1, e2) -> Float.compare(e2.getEmpSalary(), e1.getEmpSalary())).findFirst();
        System.out.println( opEmpD == null ? "No solution found" : "employee with highest salary is "+opEmpD.get());
        System.out.println("employee with highest salary is "+ highestSalary);

        //solution 4
        //Sort the collection by salary the last one is the highest
        //(get the first one for the lowest)
        Collections.sort(employeesDetails, (e1, e2) -> Float.compare(e1.getEmpSalary(), e2.getEmpSalary()));
        System.out.println("employee with highest salary is "+ employeesDetails.get(employeesDetails.size()-1));

    }
}

//simplified for to make it more of an mre
class EmployeesDetails {

    private final String empName;
    private final Float empSalary;

    public EmployeesDetails(String empName, Float empSalary) {
        this.empName = empName;
        this.empSalary = empSalary;
    }

    @Override
    public String toString() {
        return "EmployeesDetails{" +
                "Name='" + empName + '\'' +
                ", Salary='" + empSalary+ '\'' +
                '}';
    }

    public String getEmpName() {
        return empName;
    }

    public Float getEmpSalary() {
        return empSalary;
    }
}

---

See: https://stackoverflow.com/help/minimal-reproducible-example

Answer 2

Calculate maximum and minimum salary at the time of input, because you are taking input for only one time, so I think this solution will help you.

 import java.util.*;

class EmployeesDetails {
    System.out.println("Welcome Aboard!");
    Scanner emp = new Scanner(System.in);
    // add these parameters to hold min and max values for salary and employees
    float maxSalary = Float.MIN_VALUE;
    float minSalary = Float.MAX_VALUE;
    EmployeesDetails maxSalaryEmployee = null;
    EmployeesDetails minSalaryEmployee = null;
    List<EmployeesDetails> employeesDetails = new ArrayList<>();
    Boolean empQuestion = true;

    while (empQuestion == true) {
        System.out.println("Do you want to enter the employee details? Yes or No");
        String inputString = emp.next();
        empQuestion = inputString.equalsIgnoreCase("Yes") ? true : false;

        if (empQuestion == false) {
            System.out.println("Come again Later!");
            break;
        }

        System.out.println("Enter the employee name: ");
        String empName = emp.next();

        System.out.println("Enter the employee ID");
        String empID = emp.next();

        System.out.println("Enter the employee Phone number");
        String empPhoneNumber = emp.next();

        System.out.println("Enter the employee Salary");
        Float empSalary = emp.nextFloat();

        EmployeesDetails employee = new EmployeesDetails(empName, empID, empPhoneNumber, empSalary);
        employeesDetails.add(employee);
        // for max salary calculation
        if(employee.getEmpSalary() > maxSalary){
         maxSalary = employee.getEmpSalary();
         maxSalaryEmployee = employee;
        }
        // for min salary calculation
        if(employee.getEmpSalary() < minSalary){
         minSalary = employee.getEmpSalary();
         minSalaryEmployee = employee;
        }
        System.out.println(employeesDetails);
    }

        System.out.println("Max Salary Employee: " + maxSalaryEmployee);
        System.out.println("Min Salary Employee: " + minSalaryEmployee);
    emp.close();
}