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0 pointscoldtea9y ago0 comments

>For PR reasons, they didn't want to have "pointers" (arithmetic, etc. ew). So Java has "references"

Well, it's just a rename for PR reasons. They actually don't have pointers.

>But what happens when you call a method on a null reference? Not NullReferenceException, but NullPointerException.

That's because it's the underlying pointer access that causes the exception. Doesn't mean the reference is itself a pointer -- it just abstracts over one.

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3 comments · 1 top-level

paulddraper9y ago· 2 in thread

> They actually don't have pointers.

They do. Everywhere.

Every Java variable of Object type is a pointer. (Also, they're all nullable....ugh.)

If Java had real references (see original comment by jasode) you'd be able to write something like C#'s int.TryParse ( https://msdn.microsoft.com/en-us/library/f02979c7(v=vs.110).... ).

coldteaOP9y ago

>Every Java variable of Object type is a pointer.

No, it's a reference. It just has a pointer underneath.

>If Java had real references (see original comment by jasode) you'd be able to write something like C#'s int.TryParse

If Java had one specific type of references. The common use of the term though is still what Java has.

paulddraper9y ago

> The common use of the term though is still what Java has.

The way you are defining "reference" makes it immaterially different from "pointer".

Can a pointer be null? Yes, in C.

Can a "reference" be null? Yes, in Java.

Can a pointer be used in arithmetic operations? Yes, in C.

Can a pointer not be used in arithmetic operations? Yes, in Go.

If this is really the common definition, it isn't a useful one.

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