nsIVersionComparator

From MDC

nsIVersionComparator can be used to compare version strings.

Introduced in: Gecko 1.8

LXR: http://lxr.mozilla.org/seamonkey/source/xpcom/base/nsIVersionComparator.idl

Example in JavaScript:

function compareVersions(a,b) {
 var x = Components.classes["@mozilla.org/xpcom/version-comparator;1"]
                   .getService(Components.interfaces.nsIVersionComparator)
                   .compare(a,b);
 if(x == 0)
   return a + "==" + b;
 else if(x > 0)
   return a + ">" + b;
 return a + "<" + b;
}
dump(compareVersions("1.0pre", "1.0"));