Edit Question - KnowledgeHub

Title Body

Why can't I use setTimeout in a javascript object? Message = function () { ... ... this.messageFactory = ... this.feedbackTag = document.getElementById('feedbackMessages'); this.addInfo = function (message) { var info = this.messageFactory.createInfo(message); // create a div this.feedbackTag.appendChild(info); setTimeout('this.feedbackTag.removeChild(info)', 5000); // why in here, it complain this.feedbacktag is undefined ?????? }; } Thanks for Steve`s Solution, now it will work if the code is as below... because the 'this' before was actually pointing to the function within setTimeOut, it cannot rearch Message. Message = function () { ... ... this.messageFactory = ... this.feedbackTag = document.getElementById('feedbackMessages'); this.addInfo = function (message) { var info = this.messageFactory.createInfo(message); // create a div this.feedbackTag.appendChild(info); var _this = this; setTimeout(function() { _this.feedbackTag.removeChild(info); }, 5000); }; } But why doesn`t it work if we do this: Message = function () { ... ... this.messageFactory = ... this.feedbackTag = document.getElementById('feedbackMessages'); // public function this.addInfo = function (message) { var info = this.messageFactory.createInfo(message); // create a div this.feedbackTag.appendChild(info); delayRemove(info); }; // private function function delayRemove(obj) { var _this = this; setTimeout(function() { _this.feedbackTag.removeChild(info); }, 5000); } }

Tags (comma-separated) Cancel