如何檢查在ArrayList中是否存在寫入掃描器的值?檢查ArrayList中是否存在值
List<CurrentAccount> lista = new ArrayList<CurrentAccount>();
CurrentAccount conta1 = new CurrentAccount("Alberto Carlos", 1052);
CurrentAccount conta2 = new CurrentAccount("Pedro Fonseca", 30);
CurrentAccount conta3 = new CurrentAccount("Ricardo Vitor", 1534);
CurrentAccount conta4 = new CurrentAccount("João Lopes", 3135);
lista.add(conta1);
lista.add(conta2);
lista.add(conta3);
lista.add(conta4);
Collections.sort(lista);
System.out.printf("Bank Accounts:" + "%n");
Iterator<CurrentAccount> itr = lista.iterator();
while (itr.hasNext()) {
CurrentAccount element = itr.next();
System.out.printf(element + " " + "%n");
}
System.out.println();
equals()方法應該在CurrentAccount中被覆蓋以確定它們何時是同一個對象 – Javi 2010-12-09 23:28:16
在這種情況下,hashcode()也需要被覆蓋。每hashcode()合約等於對象必須具有相同的散列碼。 – zockman 2010-12-09 23:46:40