convert string to array not working

Question

Im running through a list and extracting the position value from each record

string allPositionsListed = "";
int lastRecord = volunteerAssignmentList.Count;
int currentRecord = 0;
foreach (Volunteer va in volunteerList)
{
  currentRecord++;
  if (currentRecord == lastRecord)
  {
      allPositionsListed += va.Position;
  }
  else
  {
     allPositionsListed += va.Position + ",";
  }
}

//allPositionsListed returns: "51000785,52012986"

I have written a query extracting all the records from the positionTable where position is found.. if I use

var allPositions = new string[] { "51000785", "52012986" };

List<PositionTable> positionList = (from p in DbContext.PositionList
                 where allPositions.Contains(p.Position)
                select p).ToList();

this returns the correct results...but as the allPositions values may be different how do I convert it to the necessary string array. ive tried

var allPositions2 = allPositionsListed.ToArray();

but this returns 
[0]5
[1]1
[2]0
[3]0
[4]7
etc...

when I need 
[0]51000785
[1]52012986

DavidG · Accepted Answer · 2017-08-22 00:56:35Z

2

Instead of generating a string from your initial data, you can go directly to an enumerable, something like this should work:

var allPositions = volunteerList
    .Select(v => v.Position)
    .ToList();

Which will allow you to now do this:

var positionList = (from p in DbContext.PositionList
                    where allPositions.Contains(p.Position)
                    select p)
    .ToList();

answered Aug 22, 2017 at 0:56

DavidG

120k13 gold badges232 silver badges239 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Mohsen Kamrani · Accepted Answer · 2017-08-22 00:52:28Z

1

Simply use the Split method:

var allPositionsListed = "51000785,52012986";
var allPositions2 = allPositionsListed.Split(',');

allPositions2 will be:
allPositions2[0] -> "51000785"
allPositions2[1] -> "52012986"

If you see the KB, it says this about the output of the String#ToArray method

An array that contains the elements from the input sequence.

So, it is working as expected (of course)! and you need to use the right method.

answered Aug 22, 2017 at 0:52

Mohsen Kamrani

7,4975 gold badges48 silver badges73 bronze badges

5 Comments

DavidG Over a year ago

While your answer is correct, there's no need to even generate the string in the first place.

Mohsen Kamrani Over a year ago

@DavidG, Yes, but I wanted to point exactly to where the problem is. Definitely the problem could be solved by using just the contains method but he wouldn't realize that he's calling the wrong method for the purpose.

DavidG Over a year ago

Even your answer would ultimately lead to uing Contains too.

Mohsen Kamrani Over a year ago

@DavidG, yes, and what's wrong with that. Read the title of the question again please, then decide how the answer should look like.

DavidG Over a year ago

All I'm saaying is that there was no need to do this at all, it's a waste of resources.

Collectives™ on Stack Overflow

convert string to array not working

2 Answers 2

Comments

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related