ESR研发中心 CTO兼创始人 王加杉

ters are processed in the order in which they appear, which allows you to optimize your queries for your document structure.    Element Selectors:   * 　　　any element   E　　　 an element with the tag E   E　　　 F All descendent elements of E that have t

.2.4.2的一段话：   Object.prototype.toString ( )   When the toString method is called, the following steps are taken:   1.If the this value is undefined, return "[object Undefined]". 2.If the this value is null, return "[object Null]"