title: What do the "%s", "%d" etc. mean in Delphi programming?
body: <p>Everytime I look at some of the more expert code online I see things like <code>%s</code> and <code>%d</code> in some strings, especially in dialogs, but I have no idea what they are. I have googled the terms and I can't seem to find the answer and whether it is Delphi-bound or something common to every programming language.</p>
  
  <p>I saw a post relating to C saying that it is used to "convert variables at runtime", how many arguments can we specify in a single string if this is the case?</p>
  
  <p>Example usage:</p>
  
  <pre><code>ShowMessageFmt('Day %d = %s',[i,Days[i]]);
  </code></pre>
  
  <p>found at <a href="http://www.delphibasics.co.uk/Article.asp?Name=Arrays" rel="noreferrer">Delphi Basics</a>.</p>