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PODelphi : Handling the fact that Strings are not Objects
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  1. PODelphi : Handling the fact that Strings are not Objects
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    copied!<p>I am trying to write a function that takes any TList and returns a String representation of all the elements of the TList.</p> <p>I tried a function like so</p> <pre><code>function ListToString(list:TList&lt;TObject&gt;):String; </code></pre> <p>This works fine, except you can't pass a <code>TList&lt;String&gt;</code> to it.</p> <pre><code>E2010 Incompatible types: 'TList&lt;System.TObject&gt;' and 'TList&lt;System.string&gt;' </code></pre> <p>In Delphi, a String is not an Object. To solve this, I've written a second function:</p> <pre><code>function StringListToString(list:TList&lt;string&gt;):String; </code></pre> <p>Is this the only solution? Are there other ways to treat a String as more 'object-like'?</p> <p>In a similar vein, I also wanted to write an 'equals' function to compare two TLists. Again I run into the same problem</p> <pre><code>function AreListsEqual(list1:TList&lt;TObject&gt;; list2:TList&lt;TObject&gt;):boolean; </code></pre> <p>Is there any way to write this function (perhaps using generics?) so it can also handle a <code>TList&lt;String&gt;</code>? Are there any other tricks or 'best practises' I should know about when trying to create code that handles both Strings and Objects? Or do I just create two versions of every function? Can generics help?</p> <p>I am from a Java background but now work in Delphi. It seems they are lately adding a lot of things to Delphi from the Java world (or perhaps the C# world, which copied them from Java). Like adding equals() and hashcode() to TObject, and creating a generic Collections framework etc. I'm wondering if these additions are very practical if you can't use Strings with them.</p> <p>[edit: Someone mentioned TStringList. I've used that up till now, but I'm asking about TList. I'm trying to work out if using TList for everything (including Strings) is a cleaner way to go.]</p>
 

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