java - 列表迭代类型不匹配

Question

List holder = new List();
holder.add(new JTabbedPane());
holder.add(new JTabbedPane());

for(JTabbedPane tab : holder)
{
    System.out.println(tab.toString());
}

为什么在 for-each 循环中显示类型不匹配错误？

Answer 1

试试这个

ArrayList<JTabbedPane> holder = new ArrayList<JTabbedPane>();
        holder.add(new JTabbedPane());
        holder.add(new JTabbedPane());
        for (JTabbedPane jTabbedPane : holder) {
            System.out.println(holder.toString());
        }