For further consideration... (original) (raw)

Reinier Zwitserloot reinier at zwitserloot.com
Wed Mar 25 10:04:08 PDT 2009

Excellent point about the disconnection between x?[0] where x is null
and x is the empty array. I agree: That shouldn't be in the elvis
operators proposal.

Arrays aren't nearly as common as member access anyway.

--Reinier Zwitserloot

On Mar 25, 2009, at 17:44, Tim Keith wrote:

I would like to suggest at least leaving out ?[]

The example in the proposal is not very compelling: class Group { Person[] members; // null if no members } class Person { String name; // may be null } final String aMember = g?.members?[0]?.name ?: "nobody"; If members is null you get "nobody" but if members is empty (the logical way to signify "no members") you get ArrayIndexOutOfBoundsException. "array?[...]" is like saying: if array is null treat it like it's an infinitely long array of nulls. "object?.member" is like saying: if object it null, treat it like every field is null and every method returns null. The array analog to that should be that "array?.length" means array == null ? 0 : array.length -- Tim On Tue, Mar 24, 2009 at 4:18 PM, Joseph D. Darcy <Joe.Darcy at sun.com> wrote:

Jeremy Manson wrote: Joe,

Is it all the Elvis operators, or just ?: ?

The more modest version is more likely to get in. -Joe

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