How do I make a growing listbox?

I have a pushbutton that prints a string in Value 1 of the listbox. I want to add more strings to the listbox, but i keep getting this message: Single-selection 'listbox' control requires that 'Value' be an integer within Character vector range. Basically, I want to be able to keep adding strings to my listbox, as in, adding a string as Value 2, Value 3, etc.

Answer 1

[Ameer Hamza]

Are you using uilistbox? Try this

u = uilistbox('Items', {'item1', 'item2', 'item3'}); % original uilist have 3 items

% add a new item
u.Items(end+1) = {'item4'};

[Anthony Gaetani]

I am not using uilistbox. I have a pushbutton that is supposed to send a value (ex: '2') to the listbox. Instead of adding this value to the next item, it replaces the first one.

[Ameer Hamza]

Can you show your current code or a small example of what you are trying to do.