Hi Gianluca,
`var` was introduced to Groovy just for the better compatibility of Java.
Java just supports declaring variables with `var`, so does Groovy.
Cheers,
Daniel Sun
On 2024/11/21 10:37:23 Gianluca Sartori wrote:
> Hello everybody,
>
> My name is Gianluca Sartori, from Italy, I am the author of the open source
> project Dueuno Elements (https://github.com/dueuno-projects/dueuno-elements)
> and I am new to this list.
>
> I would like to start using the more Java-ish `var` instead of the
> Python-ish `def` lexicon but I came across the fact that I cannot use `var`
> as method return type placeholder.
>
> My understanding is that I can use `var` for both local variables and class
> fields/properties but I cannot use it, for example, if I want to have a
> read only property. The code below does not compile:
>
> class C {
> var firstname
> var lastname
>
> var getFullname() {
> return firstname + ' ' + lastname
> }
> }
>
> var c = new C(firstname: 'Gianluca', lastname: 'Sartori')
> c.fullname
>
> I'd like to switch to using `var` as a type placeholder, but having to use
> `var` for variable declaration and keep using `def` for methods definition
> is something I don't understand. I love Groovy because it is easy. This
> restriction of the `var` type placeholder forces me to write code that
> mixes Python lexicon the new Java lexicon.
>
> My main worry is with Grails controllers where we need to define an action
> using `def` (or `Object`) as return type and define variables in the method
> body. At the moment we have the following options:
>
> *def* index() {
> *def* myVar = ...
> }
>
> *def* index() {
> *var* myVar = ...
> }
>
> *def* index() {
> *Object* myVar = ...
> }
>
> *Object* index() {
> *def* myVar = ...
> }
>
> *Object* index() {
> *var* myVar = ...
> }
>
> *Object* index() {
> *Object* myVar = ...
> }
>
> I would like to write controllers like this:
>
> *var* index() {
> *var* myVar = ...
> }
>
> to keep the code clean and coherent with the Groovy documentation that
> states clearly that *"If you think of def and var as an alias of Object,
> you will understand in an instant."*
>
> Is this enough of an argument to ask for an implementation of `var` that is
> fully intrechangable with `def`?
>
> Please let me know what is your opinion on that,
> cheers,
> Gianluca
>
> Gianluca Sartori
> --
> Cell. +39 388 1026822
>
