JS实现url拼接参数

function addExtraParam(url, p) {
  var index = url.indexOf('?'),
    setSearchStr = function(str, p) {
      var refes = str.split('&'),
        item = null
      sp = {}
      for (var i = 0; i < refes.length; i++) {
        item = refes[i]
        var iArr = item.split('=')
        if (iArr[0]) {
          sp[iArr[0]] = iArr[1]
        }
      }
      return $.param($.extend(sp, p))
    }
  if (index === -1) {
    var arr = url.split('#')
    return (
      arr[0] +
      '?' +
      $.param(p) +
      (arr[1] && arr[1].length > 0 ? '#' + arr[1] : '')
    )
  } else {
    var arr = url.split('?'),
      tem = arr[1]
    if (tem && tem !== '') {
      var arr3 = tem.split('#'),
        search = ''
      if (arr3.length > 1) {
        return arr[0] + '?' + setSearchStr(arr3[0], p) + '#' + arr3[1]
      } else {
        return arr[0] + '?' + setSearchStr(arr3[0], p)
      }
    }
    return arr[0]
  }
  return url
}