Could someone explain to me the difference between
is a set of elements of a defined type. It is an ordered data structure, meaning values can be accessed by their indexes.
ArrayList<string> lista = new ArrayList<>(); lista.add("Stack"); lista.add("Overflow");
That would be something like
Index | Elemento 0 | "Stack" 1 | "Overflow"
These elements can be accessed by their index.
String str1 = lista.get(0); //str1 receberá "Stack"
It is a set of key-value pairs, for each element (value) saved in a
HashMap there must be a unique key attached to it. Elements in a
HashMap must be accessed by their keys.
HashMap<Integer, String> hashMap = new HashMap<>(); hashMap.put(1, "Stack"); hashMap.put(5, "Overflow");
This would be something like:
Key | Value 1 | "Stack" 5 | "Overflow"
These elements can be accessed by the key
String str = map.get(5); //str receberá "Overflow"