Question

i have string[] _comboBoxItems which has 271 elements like

a1 03154643
a1 03450324
a2 08432155
a1 13549812

now i want to search in this array. If i write 03 i want to get

a1 03154643
a1 03450324

how can i ignore a1 (first tree letters). I want to use comboBoxItems .startswith() but i don’t know how to remove a1 when searching

Answer 1

You need to first select the substring that starts from the fourth character of each item:

var text = "03";
var matches = comboBox.Items.OfType<string>()
                            .Where(s => s.SubString(3).StartsWith(text));

The query uses OfType to make sure that you are only going to process strings and to cast them appropriately.

Update: If there are going to be strings with length < 3 characters inside the combo box (which from your description does sound unlikely), then you should also check for that eventuality:

var matches = comboBox.Items.OfType<string>()
                          .Where(s => s.Length > 3 && s.SubString(3).StartsWith(text));