jquery判断是否存在元素
if ( $("#someID").length > 0 ) {}
jquery事件
- contextmenu : 浏览器右击菜单
- click, dbclick
- mousedown, mouseup, mouseover, mouseout, mouseenter, mouseleave, mousemove
- keydown/keyup
jquery offset
- $('#mdn-dialog').offset({top:100,left:0});
跳出each循环
return false 结束当前each循环，return 继续下一次循环