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