Null Exception handling in foreach loop

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I am having the list X with some string and null value . I am iterating the foreach loop to bind the value to the textbox. If I get any null values in my list X the foreach loop get terminated and getting the null exception how to handle it.

I am checking the condition inside the for each loop. but i tnink it not correct logcally.

SPList _listObj = web.Lists[new Guid(listID)];
            SPListItem item = _listObj.GetItemById(Convert.ToInt32(itemID));
           foreach (SPField field in _listObj.Fields)
            {
                if (field.Title != Null)
                {  //do some code}}

Try below code:

foreach(var x in Lists.Where(x => x.fiels != null))
{

}

Why does .NET foreach loop throw NullRefException when , NET foreach loop throw NullRefException when collection is null? does foreach handle null c# Assert to catch the problem before the exception occurs. Null Exception handling in foreach loop. 3. How to avoid null checking before foreach IList. 2. Check an object is not null before iterating over it. 0.

That code looks pretty suspicious to me.

Firstly, do you really have a list of lists? If so, I'd imagine you have to iterate over each element in the inner list as well:

foreach(List list in Lists)
{
    foreach (var x in list)
    {
        if (x.fields != null)
            // blah
        else
            // blah
    }
}

Secondly, are you sure that the Lists variable doesn't contain any nulls? Possibly it's actually x which is null, and that's the cause of your Null Reference Exception:

foreach(List x in Lists)
{
    if (x != null && x.fields != null)
        // blah
    else
        // blah
}

Null Check Before Foreach � Issue #2727 � dotnet/csharplang � GitHub, I would like to request adding the ? null check before a foreach loop. would catch the exception, either run the rest of the code after the loop� I have a foreach loop that breaks during the loop in the condition of the foreach itself. Is there a way to try catch the item that throws the exception and then continue the loop? This will run a few times until the exception hits and then end.

The code provided is not correct. I suppose you want to check X for Null in foreach loop. If this is logically correct or not, instead only you may know as logic goes beyond the code provided and depends on where you actually use it.

I personally don't find nothing bad to check for nulls in foreach loop.

You also, for example, can use Linq to query first for Null values and after Non Null values. The matter of design choice.

Regards.

Error Handling in ForEach Loop - PowerShell General, Error Handling in ForEach Loop But i am not sure how to handle the error's in it . -harddisk $disk1 -CapacityKB $New_SizeKB -Confirm:$false | out-null. Empty collection references do not throw a NullPointerException when accessed in a for loop using iterators, the loop simply exits without any iteration. On the other hand, null collection references do throw a NullPointerException when accessed in a for loop. This behavior can be tested with the following:

List x in Lists? You probably mean to do:

foreach(string x in listvar){
    if(x != null)
       // do something
}

And are the strings actually null or just empty? That is a difference.

foreach(string x in listvar){
    if(x != "")
       // do something
}

I suspect that the problem is in your incorrect implementation of the foreach loop which causes to pop null errors as the objects inside the loop do not exist.

Safe foreach loops with C#, How to write safe and bullet-proof foreach loops? DoSomething(new ArrayList { item, null }); // NullReferenceException to read documentation he or she put problematic loops to try-catch block and set up a flag when catch� Value must be greater than or equal to 3."); else Console.Write(d + " "); } // Store the exception and continue with the loop. catch (Exception e) { exceptions.Enqueue(e); } }); Console.WriteLine(); // Throw the exceptions here after the loop completes.

Why don't you use it like this with null-coalescing operator

   foreach (var item in feeList ?? new List<FeeBusiness>())
   {
           // your code
   }

The ?? operator is called the null-coalescing operator. It returns the left-hand operand if the operand is not null; otherwise it returns the right hand operand.

forEach over branching over null check?, Well, what happens when you iterate over an empty collection? have another powerful advantage over dealing with null : you can't forget handling it! Instead of returning null usually throwing an exception is the more� Are you sure the objects you are passing to the method are not null? Click to expand Positive, I am passing a null-string however but that shouldn't matter because Java isn't even getting to read the lines that those variables are located on.

Doesn't that approach work, regardless of where and how often the errors occur? Post a specific example where it doesn't do what you want. create table test_tbl(a number,b number); declare a number; b number; begin a := 0; b := 0; for x in 1..5 loop begin savepoint s; a := a+x; b := 1/(6-a); insert into test_tbl values(a,b); exception when others then rollback to savepoint s; end; end loop

foreach ($server in $servers) { try { $null = Test-Connection -ComputerName $server -Count 1 -ErrorAction STOP Write-Output "$server - OK" } catch { Write-Output "$server - $($_.Exception.Message)" } } When the foreach loop is executed, it will then look something like this:

This solves casting exceptions but my problem is that i have a "not supported" exception ("System.Management.ManagementException"). On this case im trying to advance to next object. Still looking for a way to "continue" on exception in a foreach loop.

Comments
  • can you be more precise... the code your provide is not a valid C# code... I don't understand what goes wrong
  • please paste in the exact exception message, just saying "I get an exception" is not enough information.
  • yeah x is null how to handle it.
  • Code above has the last 2 brackets commented out. Obviously shouldn't be the case or it wouldn't compile. We'll just assume you didn't want to paste the irrelevancies, though, and know this.