Comparator interface in Java

A comparator interface is used to order the objects of user-defined classes. A comparator object is capable of comparing two objects of the same class. Comparator interface is used to sort the objects of a user-defined class. This interface is present in java.util package and contains 2 methods compare(Object obj1, Object obj2) and equals(Object element). Using a comparator, we can sort the elements based on data members. 
```
import java.util.List;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
 
class Student {
    String Name;
    int Age;
 
    public Student(String Name, Integer Age){
        this.Name = Name;
        this.Age = Age;
    }
    public String getName() { return Name; }
    public Integer getAge() { return Age; }

    @Override public String toString() {
        return "{Name=" + Name + ", Age=" + Age + '}';
    }
}

class MyComparator implements Comparator<Student> {
        @Override
        public int compare(Student s1, Student s2) {
            int NameCompare = s1.getName().compareTo(s2.getName());
            int AgeCompare = s1.getAge().compareTo(s2.getAge());
            return (NameCompare == 0) ? AgeCompare : NameCompare;
        }
}

class Main {
    public static void main(String[] args) {
        List<Student> al = new ArrayList<>();
        al.add(new Student("E", 22));
        al.add(new Student("A", 23));
        Collections.sort(al, new MyComparator());

        for (Student s : al) {
            System.out.println(s);
        }
    }
}
```
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