14325 2007-06-22 17:47:57 -0700 Using built-in type Constructor objects as keys fails 2007-06-22 18:27:49 -0700 1 1 1 Unclassified WebKit JavaScriptCore 523.x (Safari 3) All All RESOLVED INVALID P2 Major --- 0 awiner webkit-unassigned oldest_to_newest 6655 0 awiner 2007-06-22 17:47:57 -0700 Run the following page. In FF 2.0 and IE 7.0, you see "n b s d a m". In Safari, you just see "m"! Somehow, all of these constructors are considered the same key within an Object - this despite String == Object being false. Repros on both MacOS 419.3 and Windows 522.13.1. <html> <head> <script> var typeMap = new Object(); typeMap[Number] = "n"; typeMap[Boolean] = "b"; typeMap[String] = "s"; typeMap[Date] = "d"; typeMap[Array] = "a"; typeMap[Object] = "m"; var str = ""; for (var i in typeMap) { str += typeMap[i] + " "; } </script> </head> <body> <div id ='someId' onclick="testHtml()">Hi</div> </body> </html> 6653 1 ggaren 2007-06-22 18:27:49 -0700 This is a coincidental side-effect of the fact that Firefox and IE convert these objects to unique strings. Generally, JavaScript does not support using an object as a key. It uses strings as keys. The following fails in the same way in Firefox, even though each key is a distinct object: typeMap[new Object] = "n"; typeMap[new Object] = "b"; typeMap[new Object] = "s"; typeMap[new Object] = "d"; typeMap[new Object] = "a"; typeMap[new Object] = "m";