使用一個閉包自執行函式編寫外掛，傳入JQuery物件。

(function($){
    $.fn.extend({
        clock:function(options){
          var defaults = {height:'50px',width:'130px',fontSize:'16px',
                          backgroundColor:'white',padding:'10px'};
          options = $.extend({},defaults, options);
          var now = new Date();
          var year = now.getFullYear();
          var month = now.getMonth()+1;
          var day = now.getDate();
          var hour = now.getHours();
          var min = now.getMinutes();
          var div1 = "<div>" + year + "年" + month + "月" + day + "日"+ "</div>";
          var div2 = "<div>" + hour + "時" + min + "分" + "</div>";
          return $(this).each(function(){                  
            $(this).css({height:options.height,width:options.width,
                       fontSize:options.fontSize,backgroundColor:options.backgroundColor,
                       padding:options.padding,textAlign:'center'});
            $(this).append(div1);
            $(this).append(div2);
		  });
        }
           
	});
})(window.jQuery);

$(document).ready(function(){
  $(".time").clock();

})