title: JavaScript equivalent to printf/String.Format
body: <p>I'm looking for a good JavaScript equivalent of the C/PHP <code>printf()</code> or for C#/Java programmers, <code>String.Format()</code> (<code>IFormatProvider</code> for .NET).</p>
  
  <p>My basic requirement is a thousand separator format for numbers for now, but something that handles lots of combinations (including dates) would be good.</p>
  
  <p>I realize Microsoft's <a href="http://en.wikipedia.org/wiki/Ajax_%28programming%29" rel="noreferrer">Ajax</a> library provides a version of <code>String.Format()</code>, but we don't want the entire overhead of that framework.</p>