How does sorting works in Java with reference to Comparable and Comparator? -

i have class employee implementing comparable interface

public class employee implements comparable<employee> {          private int id;         private string name;         private int age;         private long salary;          public employee(int id, string name, int age, int salary) {         this.id = id;         this.name = name;         this.age = age;         this.salary = salary;         }          @override         public int compareto(employee emp) {         return (this.id - emp.id);         }          @override         public string tostring() {         return "[id=" + this.id + ", name=" + this.name + ", age=" + this.age + ", salary=" +             this.salary + "]";         }  } 

i have employee[] array sorting array using arrays.sort()

employee[] emparr = new employee[4]; emparr[0] = new employee(10, "mikey", 25, 10000); emparr[1] = new employee(20, "arun", 29, 20000); emparr[2] = new employee(5, "lisa", 35, 5000); emparr[3] = new employee(1, "pankaj", 32, 50000);  arrays.sort(emparr); 

my question how sorting working internally, emarr[0].compareto(emarr[1]) swap element if required?

i want know how comparison , swapping happening inside? , role comparatable's compareto(object o) , comparator's compare(o1,o2) playing ?

comparable implies natural ordering. speaking if a.compareto(b) == 0 a.equals(b) == true (this general convention isn't followed).

comparator utilized when want sort other natural order. example want order array of integers numbers appear first.

arrays.sort() using merge sort. see arrays api details.