cookie

/**
 * 创建cookie
 */
function _setCookie (cname, cvalue, exdays) {
  var d = new Date()
  d.setTime(d.getTime() + (exdays * 24 * 60 * 60 * 1000))
  var expires = 'expires' + d.toGMTString()
  document.cookie = cname + '=' + cvalue + '; ' + expires
}

/**
 * 获取cookie
 */
function _getCookie (cname) {
  var name = cname + '='
  var ca = document.cookie.split('; ')
  for (var i = 0; i < ca.length; i++) {
    var c = ca[i].trim()
    if (c.indexOf(name) == 0) return c.substring(name.length, c.length)
  }
  return ''
}

/**
 * 删除cookie
 */
function _delCookie (name) {
  var exp = new Date()
  exp.setTime(exp.getTime() - 1)
  var cval = getCookie(name)
  if (cval !== null) {
    var expires = 'expires' + d.toGMTString()
    document.cookie = name + '=' + cval + '; ' + expires
  }
}

/**
 * 清空所有cookie
 */
function _delAllCookie () {
  var arrCookie = document.cookie.split('; ')//将多个cookie分割成多个键值对
  for (var i = 0; i < arrCookie.length; i++) {
    var arr = arrCookie[i].split('=')
    if (arr.length > 0) {
      _delCookie(arr[0])
    }
  }
}
https://www.cnblogs.com/gg1234/p/5611086.html