The ToArray method of list in Java

To convert a list to an array of some type, take the string type as an example, in the following two ways:

Method 1, use the ToArray method without parameters string[] arr1=new string[list.size ()];list.toarray (arr);//At this point arr has the value in List//Method 2, Use the ToArray method with parameters string[] arr2= (string[]) List.toarray (new string[0]);//explanation of the meaning of the parameter: to store an array of elements in the list, if it is large enough Otherwise, a new array of the same run-time type is assigned for this purpose.

The following methods are incorrect:

String[] arr= (string[]) List.toarray ();//will appear java.lang.ClassCastException

Reference: List.toarray appears java.lang.ClassCastException

The ToArray method of list in Java