Insert to arraylist in specific position

Question

I am trying to insert a person's name into a specific position within my arraylist, i get an error when i run this:

public void InsertIntoArrayList(string actName, int posNum)
{
    snip
}

The user would enter the name into the name textbox then the position(index) at which to insert the string.. Any suggestions on an easier way to code this or a way i can change it?

The error i get is - that the index is out of range. i assume the conversion might be messed up?

show how you create ActorArrayList and the exact error message — ilansch, Sep 25 '13 at 07:31
Have you checked that the posNum is actually a number that you can insert to? Like within size of the ArrayList? — Yao Bo Lu, Sep 25 '13 at 07:32
System.Collections.ArrayList ActorArrayList = new System.Collections.ArrayList(); The array list is filled with 5 names from a text file, then the user is able to add new names to it via the form and it will display in a combo box. — Mirro A, Sep 25 '13 at 07:45
Are you asking a second, unrelated question with your last edit? Then clarify if your original question was answered(you can do that with the accept-button left beside an answer). Then ask another question. — Tim Schmelter, Sep 25 '13 at 08:15
yeah i had a second quick question, didnt know how to do it.. i just edited it in.. — Mirro A, Sep 25 '13 at 08:39

score 2 · Accepted Answer · edited May 23 '17 at 11:50

Indices are zero based. So the first item is at index 0 and the tenth item at index 9. ArrayList.Insert:

int posNum;
if(!int.TryParse(txtPosition.Text, out posNum))
{
    // show message
    return;
}
else if(posNum < 0 || posNum > ActorArrayList.Count)
{
    // show message
    return;
}
ActorArrayList.Insert(posNum, actName);

If you want to add the object at the end anyway, you just have to use Add:

ActorArrayList.Add(actName);

Note: you should use a strongly typed List<T> instead of a ArrayList, they are redundant meanwhile. c# When should I use List and when should I use arraylist?

score 0 · Answer 2 · answered Sep 25 '13 at 07:33

0

You could always use the .ToList on your array then the List insert function.

answered Sep 25 '13 at 07:33

Iain Brown

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Insert to arraylist in specific position

2 Answers2