Comments on: isFunction() or isObject(), that is the question ? http://dbj.org/dbj/?p=286 Creative Disruptive Feasible Mon, 23 Aug 2010 07:43:51 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: 修复 jQuery 中 isFunction 方法的 BUG - 隐遁峰 http://dbj.org/dbj/?p=286&cpage=1#comment-610 修复 jQuery 中 isFunction 方法的 BUG - 隐遁峰 Fri, 04 Jun 2010 02:29:37 +0000 http://dbj.org/dbj/?p=286#comment-610 [...] 《isFunction() or isObject(), that is the question ? 》 [...] [...] 《isFunction() or isObject(), that is the question ? 》 [...]

]]> By: 修复 jQuery 中 isFunction 方法的 BUG ｜ 前端开发吧 http://dbj.org/dbj/?p=286&cpage=1#comment-523 修复 jQuery 中 isFunction 方法的 BUG ｜ 前端开发吧 Wed, 28 Apr 2010 01:34:12 +0000 http://dbj.org/dbj/?p=286#comment-523 [...] 《isFunction() or isObject(), that is the question ? 》 [...] [...] 《isFunction() or isObject(), that is the question ? 》 [...]

]]> By: 修复jQuery中isFunction方法的BUG | My Sky http://dbj.org/dbj/?p=286&cpage=1#comment-461 修复jQuery中isFunction方法的BUG | My Sky Mon, 12 Apr 2010 15:25:55 +0000 http://dbj.org/dbj/?p=286#comment-461 [...] 《isFunction() or isObject(), that is the question ? 》 [...] [...] 《isFunction() or isObject(), that is the question ? 》 [...]

]]> By: Dusan http://dbj.org/dbj/?p=286&cpage=1#comment-81 Dusan Mon, 10 Aug 2009 09:42:40 +0000 http://dbj.org/dbj/?p=286#comment-81 There is a solution , which *should* work "everywhere, and which fails on *only* one singularity. There is only one "bomb" which is hardly possible in reality, unless someone "plants" it deliberately. For *every* other case this simple function bellow should work. <pre><code> var bomb = { toString : undefined, valueOf: function(o) {return "function BOMBA!"; }} ; // V.5 --- almost perfect ? function isF ( f ) { try { return /^\s*\bfunction\b/.test(f) ; } catch (x) { return false ; } } isF(bomb) /* true -- not OK */ isF(alert) /* true -- OK */ isF( isF ) /* true -- OK */ </code></pre> There is a solution , which *should* work “everywhere, and which fails on *only* one singularity.
There is only one “bomb” which is hardly possible in reality, unless someone “plants” it deliberately. For *every* other case this simple function bellow should work.


var bomb = { toString : undefined, valueOf: function(o) {return "function BOMBA!"; }} ;
// V.5    --- almost perfect ?
function isF ( f ) {
   try {  return /^\s*\bfunction\b/.test(f) ;
   } catch (x) {   return false ;
   }
}

isF(bomb)
/*
true  -- not OK
*/
isF(alert)
/*
true  -- OK
*/
isF( isF )
/*
true -- OK
*/
]]> By: Dusan http://dbj.org/dbj/?p=286&cpage=1#comment-79 Dusan Mon, 10 Aug 2009 09:17:15 +0000 http://dbj.org/dbj/?p=286#comment-79 Sorry Andrea, but your "solution" will not work with this argument : <pre><code> isIENativeFunction( { toString : undefined, valueOf : function () { return "function X";} } ) /* returns: true */ </code></pre> And it will throw an exception in this case : <pre><code> isIENativeFunction({ toString : undefined }) /* TypeError Number : 438 Description : Object doesn't support this property or method */ </code></pre> Etc ... I am sure, by now, you have spoted the flaw in your logic. But thanks for your comment, anyway. Sorry Andrea, but your “solution” will not work with this argument :


isIENativeFunction(
{ toString : undefined, valueOf : function () { return "function X";} }
)
/*
returns: true
*/

And it will throw an exception in this case :


isIENativeFunction({ toString : undefined })
/*
TypeError
Number : 438
Description : Object doesn't support this property or method
*/

Etc … I am sure, by now, you have spoted the flaw in your logic. But thanks for your comment, anyway.

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