Comparator summary

Comparator summary

1. Internal comparator 

public class ClassName implements Comparable<Object>{
    
    public ClassName{
    

    }
    public int compareTo(Object o){
    
        return this.-o.;// Ascending 
    }
}
Collections.sort(array);

2. External comparator 

public class MyComparator implements Comparator<Object>{
    
    public int compare(Object first,Object second){
    
        return first.-second.;// Ascending 
        //String Type is used (first.).compareTo(second.)
    }
}
Collections.sort(array,new MyComparator());

3. Anonymous inner class 

Collections.sort(array,new Comparator<Object>{
    
    public int compare(Object first,Object second){
    
        return first.-second.;
    }
});

4.Lambda

Collections.sort(array,(first,second)->{
    
    return frist.-second.
});