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**RadarBob** · Jul 31, 2002, 12:37 PM

1. I don't see how recursiveism applies to your problem, but then sometimes I can be dense.

2. You are applying recursion incorrectly. You have not provided a base case that will stop the recursive calls.

Here is the general form of a recursive function:

Code:

function Recursion (case) {
   if (base case) {
      do something
      return the result
   } else {
      simplify the case
      call the function with the simplified case
      return the result
   }
      
}

Let's say you want to add the integers 1 - 10... We'll start by passing in "10" and breaking it down. The base case is when the number reaches "1". At that point calling stops and we return with the results.

Here's a working example:

Code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>
<head>
<title>Untitled</title>
<script language="JavaScript" type="text/javascript">
<!--
function AddIntegers(aNumber) {
   total = 0;
   
   if (aNumber <= 1) {
      alert ("Returning with aNumber = " + aNumber);
      return (aNumber)   
   }
   alert ("calling AddIntegers (" + (aNumber - 1) + ")");
   total = aNumber + AddIntegers(--aNumber);
   alert ("returning with total = " + total);
   return (total);
} // function AddIntegers()
//-->
</script>

</head>
<body>
<script language="JavaScript" type="text/javascript">
<!--
sum = 0;
theNumber = 10;

sum = AddIntegers (theNumber);
alert ("sum = " + sum);
//-->
</script>

</body>
</html>

Recursion is not intuitive. But once you get it, it becomes easy. Really.

There are three keys to making recursion work:[list=1][*]Identify the basic algorithm you want to implement[*]Identify the base case[*]Make the "Recursive Leap of Faith"[/list=1]

As one textbook author put it, you must simply believe that recursion works. Because recursion is not intuitive, you will struggle with it until you make that leap of faith. And from my experience, that is absolutely true.

Once I made the leap of faith it became really fun to make looping, counting as the sample above, etc. all recursive. Recursion is cool

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