For #2, RDD is immutable.
> On Jan 18, 2016, at 8:10 PM, charles li <charles.up...@gmail.com> wrote:
>
>
> hi, great thanks to david and ted, I know that the content of RDD can be
> returned to driver using 'collect' method.
>
> but my question is:
>
>
> 1. cause we can write any code we like in the function put into 'foreach', so
> what happened when we actually write a 'return' sentence in the foreach
> function?
> 2. as the photo shows bellow, the content of RDD doesn't change after foreach
> function, why?
> 3. I feel a little confused about the 'foreach' method, it should be an
> 'action', right? cause it return nothing. or is there any best practice of
> the 'foreach' funtion? or can some one put your code snippet when using
> 'foreach' method in your application, that would be awesome.
>
>
> great thanks again
>
>
>
>
>
>> On Tue, Jan 19, 2016 at 11:44 AM, Ted Yu <yuzhih...@gmail.com> wrote:
>> Here is signature for foreach:
>> def foreach(f: T => Unit): Unit = withScope {
>>
>> I don't think you can return element in the way shown in the snippet.
>>
>>> On Mon, Jan 18, 2016 at 7:34 PM, charles li <charles.up...@gmail.com> wrote:
>>> code snippet
>>>
>>> <屏幕快照 2016-01-19 上午11.32.05.png>
>>>
>>> the 'print' actually print info on the worker node, but I feel confused
>>> where the 'return' value
>>> goes to. for I get nothing on the driver node.
>>> --
>>> --------------------------------------
>>> a spark lover, a quant, a developer and a good man.
>>>
>>> http://github.com/litaotao
>
>
>
> --
> --------------------------------------
> a spark lover, a quant, a developer and a good man.
>
> http://github.com/litaotao
