List toArray

java.util.List 中关于两个 toArray 方法的声明

Object[] toArray()

<T> T[] toArray(T[] a)

使用示例

List<String> list = new ArrayList<String>();
  list.add("str1");
  list.add("str2");

  //(String[])list.toArray();会抛异常：Exception in thread "main" java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to [Ljava.lang.String;
  //String str[] = (String[])list.toArray();
  

  // list.toArray(new String[list.size()]); 正常
  String str[] = list.toArray(new String[list.size()]);