bugong

摘要： 示例1：关于事件对象MSIE：window.event, cancelBubble, returnValue,srcElement, button（鼠标按键，1,4,2，左中右）W3C：event, stopPropagation(), preventDefault(), target, butto... 阅读全文

摘要： 示例1：var abc; console.log(abc === undefined); console.log(abc === null); console.log(typeof abc === undefined); console.log(typeof abc === 'undefin... 阅读全文