c# - How can I find the last element in a List<>?

Question

The following is an extract from my code:

public class AllIntegerIDs 
{
    public AllIntegerIDs() 
    {            
        m_MessageID = 0;
        m_MessageType = 0;
        m_ClassID = 0;
        m_CategoryID = 0;
        m_MessageText = null;
    }
    
    ~AllIntegerIDs()
    {
    }

    public void SetIntegerValues (int messageID, int messagetype,
        int classID, int categoryID)
    {
        this.m_MessageID = messageID;
        this.m_MessageType = messagetype;
        this.m_ClassID = classID;
        this.m_CategoryID = categoryID;
    }
    
    public string m_MessageText;
    public int m_MessageID;
    public int m_MessageType;
    public int m_ClassID;
    public int m_CategoryID;
}

I am trying to use the following in my main() function code:

List<AllIntegerIDs> integerList = new List<AllIntegerIDs>();

/* some code here that is ised for following assignments*/
{
   integerList.Add(new AllIntegerIDs());
   index++;
   integerList[index].m_MessageID = (int)IntegerIDsSubstring[IntOffset];
   integerList[index].m_MessageType = (int)IntegerIDsSubstring[IntOffset + 1];
   integerList[index].m_ClassID = (int)IntegerIDsSubstring[IntOffset + 2];
   integerList[index].m_CategoryID = (int)IntegerIDsSubstring[IntOffset + 3];
   integerList[index].m_MessageText = MessageTextSubstring;
}

Problem is here: I am trying to print all elements in my List using a for loop:

for (int cnt3 = 0 ; cnt3 <= integerList.FindLastIndex ; cnt3++) //<----PROBLEM HERE
{
   Console.WriteLine("{0}{1}{2}{3}{4}
", integerList[cnt3].m_MessageID,integerList[cnt3].m_MessageType,integerList[cnt3].m_ClassID,integerList[cnt3].m_CategoryID, integerList[cnt3].m_MessageText);
}

I want to find the last element so that I equate cnt3 in my for loop and print out all entries in the List. Each element in the list is an object of the class AllIntegerIDs as mentioned above in the code sample. How do I find the last valid entry in the List?

Should I use something like integerList.Find(integerList[].m_MessageText == null;?

If I use that it will need an index that will range from 0 to whatever maximum. Means I will have to use another for loop which I do not intend to use. Is there a shorter/better way?

Answer 1

To get the last item of a collection use LastOrDefault() and Last() extension methods

var lastItem = integerList.LastOrDefault();

OR

var lastItem = integerList.Last();

Remeber to add using System.Linq;, or this method won't be available.