Null Exception handling in foreach loop

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.

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
}

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.

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.

string delimitedvalues = null;//"11,22,33";
foreach(var str in (delimitedvalues?? string.Empty).split(','))
{
    string testvalue = "Test Value" + str;
}

Hope the above construct is useful!

You have to make sure that your object you are getting doesn't come back as null (your list, _listObj) before you ever iterate its fields. Even if you are certain the GUID you are passing in matches the list you are trying to get, you should be checking that object for being null, and checking for the number of fields, and if you get an item for the ID you are passing in:

SPList _listObj = web.Lists[new Guid(listID)];
if (_listObj != null)  // do we have a list object?
{
    if (_listObj.Fields.Count > 0) // do we have list columns on the list?
    {
        SPListItem item = _listObj.GetItemById(Convert.ToInt32(itemID));
        if (item != null) // did our item ID get a hit?
        {
            foreach (SPField field in _listObj.Fields)
            {
                if (field.Title != null)  // need lower case null, here
                {  
                    //do some code
                }
            }
        }
    }
}