Can I use compareTo to sort integer and double values?

Question

Can I use compareTo to sort integer and double values? My system gives me an error that I Cannot invoke compareTo(int) on the primitive type int. any ideas?

Code:

Answer 1

Step 1: Sort list by last name (for String values)

Collections.sort(peopleList, (p1, p2) -> 
                     p1.getLastName().compareTo(p2.getLastName()));

Step 2: Print all elements in the list

for (People ppl : peopleList) {
    System.out.print(ppl.getFirstName()+" - "+ppl.getLastName());
}

Step 1: Sort list by Age (for int values)

Collections.sort(peopleList, (p1, p2) -> p1.getAge() - (p2.getAge()));

Step 2: Print all elements in the list

for (People ppl : peopleList) {
    System.out.println(ppl.getAge());
}