jquery读写cookie操作实例分析

jQuery.cookie = function(name, value, options) {
if (typeof value != 'undefined') {
  options = options || {};
  if (value === null) {
  value = '';
  options = $.extend({}, options);
  options.expires = -1;
  }
  var expires = '';
  if (options.expires && (typeof options.expires == 'number' || options.expires.toUTCString)) {
  var date;
  if (typeof options.expires == 'number') {
   date = new Date();
   date.setTime(date.getTime() + (options.expires * 24 * 60 * 60 * 1000));
  } else {
   date = options.expires;
  }
  expires = '; expires=' + date.toUTCString();
  }
  var path = options.path ? '; path=' + (options.path) : '';
  var domain = options.domain ? '; domain=' + (options.domain) : '';
  var secure = options.secure ? '; secure' : '';
  document.cookie = [name, '=', encodeURIComponent(value), expires, path, domain, secure].join('');
} else {
  var cookieValue = null;
  if (document.cookie && document.cookie != '') {
  var cookies = document.cookie.split(';');
  for (var i = 0; i < cookies.length; i++) {
   var cookie = jQuery.trim(cookies[i]);
   if (cookie.substring(0, name.length + 1) == (name + '=')) {
   cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
   break;
   }
  }
  }
  return cookieValue;
}
};

$.cookie("name"); //根据cookie名字取到cookie值
$.cookie("name", "value");//设置cookie 名字，值
$.cookie("name", value, { expires: 7 }); //设置cookie 名字，值，生命周期等属性
$.cookie("name", null); //根据cookie名移除cookie