Question

I have a bit of code:

class MyClass<RCM> 
  private List<RCM> allPreExistingConfigsForCodes() {
    if(this.allCodesForThisType.size() == 0)
       return new ArrayList<RCM>(0);

IntelliJ is telling me I should replace new ArrayList<RCM> with new ArrayList<> what would that mean?

Answer 1

From the Java Tutorials generics lesson:

In Java SE 7 and later, you can replace the type arguments required to
invoke the constructor of a generic class with an empty set of type
arguments (<>) as long as the compiler can determine, or infer, the
type arguments from the context. This pair of angle brackets, <>, is
informally called the diamond. For example, you can create an instance
of Box<Integer> with the following statement:

Box<Integer> integerBox = new Box<>();