object has no hasOwnProperty method (i.e. it's undefined) - IE8
问题 This seems quite bizarre. Here's my experiment in the IE8 console: typeof obj1 // "object" obj1.hasOwnProperty // {...} typeof obj2 // "object" obj2.hasOwnProperty // undefined Any ideas as to what could cause this? 回答1: This example is from IE8, but the same return is from IE6+ and most other IE browsers. IE before #9 does not define it for host objects var o=window;// or document or document elements o.hasOwnProperty /* returned value: (undefined) undefined */ 来源: https://stackoverflow.com