NullReferenceException in If Statement

Question

Ok so when I run this i run into a null exception in the if statement on workshops[2]. The messagebox shows the value that i expected. Thoughts?

foreach (string[] workshops in data.aWorkJag)
{
    MessageBox.Show(workshops[2].ToString());
    if (workshops[1].ToString() == wkshpConfCode)
    {
        toAddList.Add(workshops[2].ToString());
    }
}

The exception is being thrown on the line

toAddList.Add(workshops[2].ToString());

You are displaying third item [2], but accessing second item [1], which I think is null — Sergey Berezovskiy, Feb 28 '14 at 01:35
toAddList.Add(workshops[2].ToString()); is what throws the null exception sorry. — SoulOfSet, Feb 28 '14 at 01:36
Welcome to Stack Overflow! Almost all cases of `NullReferenceException` are the same. Please see "[What is a NullReferenceException in .NET?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-in-net)" for some hints. — John Saunders, Feb 28 '14 at 01:54

score 1 · Accepted Answer · answered Feb 28 '14 at 01:35

Looks like workshops[2] has a value but workshops[1] is null. The ToString() method throws an exception if you call it on a null value.

Assuming that's not just a typo, you can use Convert.ToString(), which does a null check and returns an empty string:

if (Convert.ToString(workshops[1]) == wkshpConfCode)

score 1 · Answer 2 · answered Feb 28 '14 at 01:35

1

Check to make sure that toAddList is initialized

answered Feb 28 '14 at 01:35

TYY

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Did something silly and had the variable set to null. Would seem rather obvious but I do that allot. Thank you. – SoulOfSet Feb 28 '14 at 01:42

NullReferenceException in If Statement

2 Answers2