Index out bounds of array when adding data into an array

Question

So I have some code which stores some data in an array. When new data comes in it is put in a new array item (The totalnumber of array items) then the total number of array items is added too ready for the next bit of data. But when I try to add data into the array, be it array[0] or whatever it throws array index out of bounds?

Declaration:

string[] TabMessages = { };
int TotalTabs = 0;

Using it:

DevComponents.DotNetBar.TabItem Tab = TabStrip.CreateTab(TabName);
Tab.Tooltip = id + "|" + TabIndex;
TabMessages[TotalTabs] = "";//index out of bounds of array
TabStrip.SelectedTab = Tab;
TotalTabs++;

Any help, this is really annoying me because it's throwing the error about the index being out of bounds of the array when I'm trying to create a new entry to the array...

Arrays need to be allocated with the size required. If you want a dynamic array try List — atastrophic
– atastrophic, Commented Feb 18, 2013 at 4:41

Corey · Accepted Answer · 2013-02-18 04:42:47Z

2

Arrays are a static length. You have defined an array of 0 length, then tried to access an element in the array that does not exist. Either you have to create a large enough array to hold all of the values you intend to use, or use a non-static collection like List<string> instead of a static-sized one like string[].

List<string> TabMessages = new List<string>();
TabMessages.Add("");

If you want something you can access by index, but don't want to supply all possible values, use a dictionary:

Dictionary<int, string> TabMessages = new Dictionary<int, string>();
TabMessages[TotalTabs] = "";

answered Feb 18, 2013 at 4:42

Corey

16.6k2 gold badges38 silver badges76 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

carlosfigueira · Accepted Answer · 2013-02-18 04:39:55Z

1

Arrays in C# are not dynamic - they are fixed size. Try using something list a List<string> and using the Add method to insert a new entry into it.

TabMessages is an array of 0 elements (that's how you declared it). As such, you won't be able to add (or set) any element on it - you'll get an index out of bounds exception every time.

answered Feb 18, 2013 at 4:39

carlosfigueira

87.7k14 gold badges137 silver badges176 bronze badges

1 Comment

user1763295 Over a year ago

Worked perfectly. Thanks, Also thanks to everyone else that replied for helping :)

cuongle · Accepted Answer · 2013-02-18 04:47:33Z

1

This code:

string[] TabMessages = { };

is equivalent to:

string[] TabMessages = new string[0];

it means you created array which size 0. That is why you got this kind of exception. So you can use List<string> instead with dynamic size:

var TabMessages = new List<string>();

Then you can add the first item:

TabMessages.Add(string.Empty);

Or, create string array with fixed size depending on your business rule:

string[] TabMessages = new string[5];  // create string array with 5 elements

edited Feb 18, 2013 at 4:47

answered Feb 18, 2013 at 4:42

cuongle

75.5k30 gold badges155 silver badges212 bronze badges

Comments

AndrewP · Accepted Answer · 2013-02-18 04:44:59Z

0

Array's are defined as having a fixed size. Declaring string[] TabMessages = {} is the same as string[0] Tabmessages;

You can resize an array (but I think it is a moderately expensive process) - see http://www.dotnetperls.com/array-resize

Alternatively (and preferably), try using some type of List construct

answered Feb 18, 2013 at 4:44

AndrewP

1,61814 silver badges25 bronze badges

Collectives™ on Stack Overflow

Index out bounds of array when adding data into an array

4 Answers 4

Comments

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related