Automatic conversion with LINQ

Question

My VS2010 using ReSharper which prompts to converts foreach to LINQ. It converts from

foreach (var item in quotePrice.ExtraServiceBreakdown)
{
    hazmatRate = (quoteRequest.IsHazMat && item.Id == VitranHazmatCode) ?   
                                                 item.Cost : hazmatRate;
}

to

hazmatRate = quotePrice.ExtraServiceBreakdown.Aggregate(
                 hazmatRate, (current, item) => 
                     (quoteRequest.IsHazMat && item.Id == VitranHazmatCode) ? 
                         item.Cost : current);

I have two questions here,

What does current meant? Is that points to the variable hazmatRate?
What does Aggregate actually does?

The problem is that you're setting a variable in a `foreach` without breaking it, hence your always overwriting it. This is not efficient and possibly error-prone(if you don't want the last value). — Tim Schmelter, Feb 07 '13 at 09:26
On question #2, have you tried reading the documentation on Aggregate? — John Saunders, Feb 07 '13 at 09:29
@TimSchmelter, can u explain a bit more with this? **without breaking it,** — Hary, Feb 07 '13 at 09:33
@DON: You can `break` a loop when you've found what you were looking for. So assuming that you actually want to find the first item with with `id=VitranHazmatCode`, you should exit the `foreach` via `break;`. If you want to sum a number instead, you'll need to use `hazmatRate += ...` instead. — Tim Schmelter, Feb 07 '13 at 09:35
In that case also use a different Hazmat rate in the foreach loop then the one you will be increasing. — JMan, Feb 07 '13 at 09:38
@TimSchmelter yes i can understand that now and i will do that thanks — Hary, Feb 07 '13 at 09:41
@JeroenMoonen, sorry i cant understand? can u explain it pls? — Hary, Feb 07 '13 at 09:42
@JeroenMoonen, yeah i can now understood and here in my case i wont need that — Hary, Feb 07 '13 at 09:44

score 1 · Accepted Answer · edited May 23 '17 at 10:24

Current indeed point to your Hazmat
LINQ Aggregate algorithm explained

And i think you will need to do as stated in the comment by Tim:

    hazmatRate += (quoteRequest.IsHazMat && item.Id == VitranHazmatCode) ?   item.Cost : hazmatRate;

But in this case i'd change 'hazmatRate' by a base rate declared before your function. Otherwise you would be increasing your value with the value it contained before making it grow exponentially

Automatic conversion with LINQ

1 Answers1