Customer.java

public class Customer
{
 private String firstName;
 private String lastName;
 private int age;
 private String mobilePhone;

 public Customer() {
 this.firstName = "";
 this.lastName = "";
 // this.firstName = "Unknown";
 // this.lastName = "Unknown";
 this.age = 0;
 this.mobilePhone = "";
 }
 
 public Customer(String firstName, String lastName, int age, String mobilePhone) {
 this.firstName = firstName;
 this.lastName = lastName;
 this.age = age;
 this.mobilePhone = mobilePhone;
 }

 public String getFirstName() {
 return firstName;
 }

 public String getLastName() {
 return lastName;
 }

 public int getAge() {
 return age;
 }

 public String getMobilePhone() {
 return mobilePhone;
 }

 @Override
 public String toString() {
 return firstName + " " + lastName + " Age:" + age + " Mobile Phone:" + mobilePhone;
 }
}