Java Coding Problems

97. LVTI and generic types, T

In order to understand how LVTI can be combined with generic types, let's start with an example. The following method is a classical usage case of a generic type, T:

public static <T extends Number> T add(T t) {  T temp = t;  ...  return temp;}

In this case, we can replace T with var and the code will work fine:

public static <T extends Number> T add(T t) {  var temp = t;  ...  return temp;}

So, local variables that have generic types can take advantage of LVTI. Let's look at some other examples, first using the generic type, T:

public <T extends Number> T add(T t) {  List<T> numberList = new ArrayList<T>();  numberList.add(t);  numberList.add((T) Integer.valueOf(3));  numberList.add((T) Double.valueOf(3.9)); // error: ...