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copied!<p>Sure, but it's probably easier to read written like this:</p> <pre><code>var reverseArray = function(x,indx,str) { if (indx === 0) { // Termination condition return str; // return default } else { return reverseArray(x, --indx, str + " " + x[indx]); // recur on x, reduce indx, update default } } </code></pre> <p>Recursion is just a function calling itself, right? The important thing is the termination condition that prevents the function from calling itself forever. In this case that's this line:</p> <pre><code>if (indx === 0)… </code></pre> <p>As long as indx is not 0, the function will continue to call itself with updated arguments. The subsequent call does the same thing, but the final product <code>str</code> contains the value passed from the parent call to <code>reverseArray</code>. Eventually indx reaches zero and the value of str is the combined value passed down from parent to child. That is what is returned by the line:</p> <pre><code>return str; // ' lime peach orange apple' </code></pre> <p>It gets returned to its parent, and its parent returns that to its parent and so on until the top-most frame is reached.</p> <pre><code>arr = new Array('apple', 'orange', 'peach', 'lime'); reverseArray(arr,arr.length,""); // ['apple', 'orange', 'peach', 'lime'], 4, "" +['apple', 'orange', 'peach', 'lime'], 3, "" + " " + x[3] = " lime"; ++['apple', 'orange', 'peach', 'lime'], 2, " lime" + " " + x[2] = " lime peach"; +++['apple', 'orange', 'peach', 'lime'], 1, " lime peach" + " " + x[1] = " lime peach orange"; ++++['apple', 'orange', 'peach', 'lime'], 0, " lime peach orange" + " " + x[0] = " lime peach orange apple"; // indx == 0, so this string returns </code></pre>

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