Can someone please translate what this compareTo method is doing? To give some context, the assignment is to take two arraylists of Person class type and compares them based on only the email field. Comparable interface is also implemented on the person class. In the code, i am especially confused by the question mark and colon on the last line. Thank you!

public int compareTo(Person o) { int last = this.email.compareTo(o.email); //Sorting by first name if last name is same d return last == 0 ? this.email.compareTo(o.email) : last