Differences

This shows you the differences between two versions of the page.

--- collections [2018/02/04 18:42] – wolfgangriedmann
+++ collections [2018/02/05 05:20] (current) – wolfgangriedmann
@@ Line 20: / Line 20: @@
   * [[https://docs.microsoft.com/en-us/dotnet/standard/collections/commonly-used-collection-types|MSDN: Commonly used collection types]]
-But it is very important to know that you **cannot** change a collection while you are using it in a ''foreach'' loop.
+There are a few very important things you should know about collections:
+  * They are not arrays, and therefore they are **0-based**, so the first member of the collection is **element 0**, and there is no compiler switch that can change this, because it are the classes itself that are written this was
+  * You **cannot** change a collection while you are using it in a ''foreach'' loop.
+  * most collections are using generics, to you need to specify the type(s) of the elements in the declaration of the variable
+A few code samples (please look at samples for the single classes [[collections:list|System.Collections.Generic.List]] and [[collections:dictionary|System.Collections.Generic.Dictionary]]) for deeper looks):
+<code>using System.Collections.Generic
+local oList as List<string>
+local nCount as int
+oList := List<string>{}
+oList:Add( "Hi girls" )
+oList:Add( "Hi guys" )
+nCount := oList:Count
+foreach cItem as string in oList
+  // do something
+next
+oList:Remove( "Hi guys" )
+oList:RemoveAt( 0 )</code>
+<code>local oDictionary as Dictionary<int,string>
+local nCount as int
+oDictionary := Dictionary<int,string>{}
+oDictionary:Add( 1, "Hi girls" )
+oDictionary:Add( 2, "Hi guys" )
+foreach oItem as KeyValuePair<int,string> in oDictionary
+  // do something
+next</code>