function phpserialize (mixedValue) {
  //  discuss at: https://locutus.io/php/serialize/
  // original by: Arpad Ray (mailto:arpad@php.net)
  // improved by: Dino
  // improved by: Le Torbi (https://www.letorbi.de/)
  // improved by: Kevin van Zonneveld (https://kvz.io/)
  // bugfixed by: Andrej Pavlovic
  // bugfixed by: Garagoth
  // bugfixed by: Russell Walker (https://www.nbill.co.uk/)
  // bugfixed by: Jamie Beck (https://www.terabit.ca/)
  // bugfixed by: Kevin van Zonneveld (https://kvz.io/)
  // bugfixed by: Ben (https://benblume.co.uk/)
  // bugfixed by: Codestar (https://codestarlive.com/)
  // bugfixed by: idjem (https://github.com/idjem)
  //    input by: DtTvB (https://dt.in.th/2008-09-16.string-length-in-bytes.html)
  //    input by: Martin (https://www.erlenwiese.de/)
  //      note 1: We feel the main purpose of this function should be to ease
  //      note 1: the transport of data between php & js
  //      note 1: Aiming for PHP-compatibility, we have to translate objects to arrays
  //   example 1: serialize(['Kevin', 'van', 'Zonneveld'])
  //   returns 1: 'a:3:{i:0;s:5:"Kevin";i:1;s:3:"van";i:2;s:9:"Zonneveld";}'
  //   example 2: serialize({firstName: 'Kevin', midName: 'van'})
  //   returns 2: 'a:2:{s:9:"firstName";s:5:"Kevin";s:7:"midName";s:3:"van";}'
  //   example 3: serialize( {'ü': 'ü', '?': '?', '??': '??'})
  //   returns 3: 'a:3:{s:2:"ü";s:2:"ü";s:3:"?";s:3:"?";s:4:"??";s:4:"??";}'
  let val, key, okey
  let ktype = ''
  let vals = ''
  let count = 0
  const _utf8Size = function (str) {
    return ~-encodeURI(str).split(/%..|./).length
  }
  const _getType = function (inp) {
    let match
    let key
    let cons
    let types
    let type = typeof inp
    if (type === 'object' && !inp) {
      return 'null'
    }
    if (type === 'object') {
      if (!inp.constructor) {
        return 'object'
      }
      cons = inp.constructor.toString()
      match = cons.match(/(\w+)\(/)
      if (match) {
        cons = match[1].toLowerCase()
      }
      types = ['boolean', 'number', 'string', 'array']
      for (key in types) {
        if (cons === types[key]) {
          type = types[key]
          break
        }
      }
    }
    return type
  }
  const type = _getType(mixedValue)
  switch (type) {
    case 'function':
      val = ''
      break
    case 'boolean':
      val = 'b:' + (mixedValue ? '1' : '0')
      break
    case 'number':
      val = (Math.round(mixedValue) === mixedValue ? 'i' : 'd') + ':' + mixedValue
      break
    case 'string':
      val = 's:' + _utf8Size(mixedValue) + ':"' + mixedValue + '"'
      break
    case 'array':
    case 'object':
      val = 'a'
      /*
      if (type === 'object') {
        var objname = mixedValue.constructor.toString().match(/(\w+)\(\)/);
        if (objname === undefined) {
          return;
        }
        objname[1] = serialize(objname[1]);
        val = 'O' + objname[1].substring(1, objname[1].length - 1);
      }
      */
      for (key in mixedValue) {
        if (mixedValue.hasOwnProperty(key)) {
          ktype = _getType(mixedValue[key])
          if (ktype === 'function') {
            continue
          }
          okey = (key.match(/^[0-9]+$/) ? parseInt(key, 10) : key)
          vals += phpserialize(okey) + phpserialize(mixedValue[key])
          count++
        }
      }
      val += ':' + count + ':{' + vals + '}'
      break
    case 'undefined':
    default:
      // Fall-through
      // if the JS object has a property which contains a null value,
      // the string cannot be unserialized by PHP
      val = 'N'
      break
  }
  if (type !== 'object' && type !== 'array') {
    val += ';'
  }
  return val
}