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
>>
>>
>>
>> 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
