List recycling remove () method

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notes

Sometimes knock Code encounter this situation, a circulation list, perform a complete removal of going after it, and then continue the cycle, if not pay attention to write easily run error: java.util.ConcurrentModificationException.

In reading "Java programming ideas" to see a good writing, could not help wondering record, here referred to as a method, in addition to a commonly used method, referred to as the second method, the following two methods Code:

method one

List<String> list = new ArrayList<>();
list.add("1");
list.add("2");
list.add("3");

if (list.size() > 0){
    for (String s:new ArrayList<>(list)){
        System.out.println(s);
        list.remove(s);
    }
}
/*
    Output : 1
             2
             3
 */

Method Two

List<String> list = new ArrayList<>();
list.add("1");
list.add("2");
list.add("3");

if (list.size() > 0){
    for (int i = list.size() - 1; i >= 0; i--){
        System.out.println(list.get(i));
        list.remove(i);
    }
}
/*
    Output : 3
             2
             1
 */

to sum up

Personally I prefer to use a method, but will not know what's hidden it ~