How to lowercase every element of a collection efficiently?

Question

What\'s the most efficient way to lower case every element of a List or Set?

My idea for a List:

final List strings = new ArrayList<         


        

Answer 1

Referring to the ListIterator method in the accepted (Matthew T. Staebler's) solution. How is using the ListIterator better than the method here?

public static Set replace(List strings) {
    Set set = new HashSet<>();
    for (String s: strings)
        set.add(s.toLowerCase());
    return set;
}