Eclipse bug? When is a short not a short?

Question

Is this a bug in Eclipse?

When declaring a short variable the compiler treats the the integer literal as a short.

// This works
short five = 5;


        

Answer 1

It's because when invoking a method, only primitive widening conversions are authorised, not primitive narrowing conversions (which int -> short is). This is defined in the JLS #5.3:

Method invocation contexts allow the use of one of the following:

• an identity conversion (§5.1.1)
• a widening primitive conversion (§5.1.2)
• a widening reference conversion (§5.1.5)
• a boxing conversion (§5.1.7) optionally followed by widening reference conversion
• an unboxing conversion (§5.1.8) optionally followed by a widening primitive conversion.

On the other hand, in the case of an assignment, narrowing conversion is allowed, provided that the number is a constant and fits within a short, cf JLS #5.2:

A narrowing primitive conversion may be used if the type of the variable is byte, short, or char, and the value of the constant expression is representable in the type of the variable.