如果窗口不是框架/iframe，则为真:

This is true if a window is not a frame/iframe:

if(self==top)

如果您想查看给定窗口的父窗口是否为框架，请使用:

If you like to see if the parent window of the given window is a frame, use:

if(parent==top)

这是top(窗口层次结构的最顶层窗口)和另一个窗口对象(self 或parent)的简单比较.

It's a simple comparision of top (the most top window of the window hierarchy) and another window object (self or parent).