Assignment Compatibility

Assignment compatibility requires that the type of the expression on the left-hand side of the assignment is assignment‑compatible with the expression on the right-hand side.

A value t2 of type T2 is assignment-compatible with a value t1 of type T1 (that is, t1 := t2 is allowed) if any of the following is true.

T1 is an interface and T2 is a class that implements the interface
T1 and T2 are identical types
T2 is a subclass of T1
T1 is a String primitive type and T2 is a Character primitive type
T1 is a Real primitive type and T2 is a Byte, Integer, Integer64, or Decimal primitive type
T1 is a Decimal primitive type and T2 is a Byte, Integer, Integer64, or Real primitive type
T1 is an Integer primitive type and T2 is a Byte primitive type
T1 is an Integer64 primitive type and T2 is an Integer or Byte primitive type

JADE provides a type-safe mechanism to assign a superclass reference to a declared subclass reference. For details, see "Type Guard Expression", earlier in this chapter.