compareto method java

String str1 = "Negan";  
String str2 = ""; //empty string

//it would return the length of str1 in positive number
str1.compareTo(str2); // 5

//it would return the length of str1 in negative number
str2.compareTo(str1); //-5

public int compareTo(Jedi jedi){
    return this.age > jedi.age ? 1 : this.age < jedi.age ? -1 : 0;
}