---
layout: page
title: "JavaScript unserialize function"
comments: true
sharing: true
footer: true
alias:
- /functions/view/unserialize:571
- /functions/view/unserialize
- /functions/view/571
- /functions/unserialize:571
- /functions/571
---
<!-- Generated by Rakefile:build -->
A JavaScript equivalent of PHP's unserialize

{% codeblock var/unserialize.js lang:js https://raw.github.com/kvz/phpjs/master/functions/var/unserialize.js raw on github %}
function unserialize (data) {
  // From: http://phpjs.org/functions
  // +     original by: Arpad Ray (mailto:arpad@php.net)
  // +     improved by: Pedro Tainha (http://www.pedrotainha.com)
  // +     bugfixed by: dptr1988
  // +      revised by: d3x
  // +     improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +        input by: Brett Zamir (http://brett-zamir.me)
  // +     improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +     improved by: Chris
  // +     improved by: James
  // +        input by: Martin (http://www.erlenwiese.de/)
  // +     bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +     improved by: Le Torbi
  // +     input by: kilops
  // +     bugfixed by: Brett Zamir (http://brett-zamir.me)
  // +      input by: Jaroslaw Czarniak
  // +     improved by: Eli Skeggs
  // %            note: We feel the main purpose of this function should be to ease the transport of data between php & js
  // %            note: Aiming for PHP-compatibility, we have to translate objects to arrays
  // *       example 1: unserialize('a:3:{i:0;s:5:"Kevin";i:1;s:3:"van";i:2;s:9:"Zonneveld";}');
  // *       returns 1: ['Kevin', 'van', 'Zonneveld']
  // *       example 2: unserialize('a:3:{s:9:"firstName";s:5:"Kevin";s:7:"midName";s:3:"van";s:7:"surName";s:9:"Zonneveld";}');
  // *       returns 2: {firstName: 'Kevin', midName: 'van', surName: 'Zonneveld'}
  var that = this,
    utf8Overhead = function (chr) {
      // http://phpjs.org/functions/unserialize:571#comment_95906
      var code = chr.charCodeAt(0);
      if (code < 0x0080) {
        return 0;
      }
      if (code < 0x0800) {
        return 1;
      }
      return 2;
    },
    error = function (type, msg, filename, line) {
      throw new that.window[type](msg, filename, line);
    },
    read_until = function (data, offset, stopchr) {
      var i = 2, buf = [], chr = data.slice(offset, offset + 1);

      while (chr != stopchr) {
        if ((i + offset) > data.length) {
          error('Error', 'Invalid');
        }
        buf.push(chr);
        chr = data.slice(offset + (i - 1), offset + i);
        i += 1;
      }
      return [buf.length, buf.join('')];
    },
    read_chrs = function (data, offset, length) {
      var i, chr, buf;

      buf = [];
      for (i = 0; i < length; i++) {
        chr = data.slice(offset + (i - 1), offset + i);
        buf.push(chr);
        length -= utf8Overhead(chr);
      }
      return [buf.length, buf.join('')];
    },
    _unserialize = function (data, offset) {
      var dtype, dataoffset, keyandchrs, keys, contig,
        length, array, readdata, readData, ccount,
        stringlength, i, key, kprops, kchrs, vprops,
        vchrs, value, chrs = 0,
        typeconvert = function (x) {
          return x;
        };

      if (!offset) {
        offset = 0;
      }
      dtype = (data.slice(offset, offset + 1)).toLowerCase();

      dataoffset = offset + 2;

      switch (dtype) {
        case 'i':
          typeconvert = function (x) {
            return parseInt(x, 10);
          };
          readData = read_until(data, dataoffset, ';');
          chrs = readData[0];
          readdata = readData[1];
          dataoffset += chrs + 1;
          break;
        case 'b':
          typeconvert = function (x) {
            return parseInt(x, 10) !== 0;
          };
          readData = read_until(data, dataoffset, ';');
          chrs = readData[0];
          readdata = readData[1];
          dataoffset += chrs + 1;
          break;
        case 'd':
          typeconvert = function (x) {
            return parseFloat(x);
          };
          readData = read_until(data, dataoffset, ';');
          chrs = readData[0];
          readdata = readData[1];
          dataoffset += chrs + 1;
          break;
        case 'n':
          readdata = null;
          break;
        case 's':
          ccount = read_until(data, dataoffset, ':');
          chrs = ccount[0];
          stringlength = ccount[1];
          dataoffset += chrs + 2;

          readData = read_chrs(data, dataoffset + 1, parseInt(stringlength, 10));
          chrs = readData[0];
          readdata = readData[1];
          dataoffset += chrs + 2;
          if (chrs != parseInt(stringlength, 10) && chrs != readdata.length) {
            error('SyntaxError', 'String length mismatch');
          }
          break;
        case 'a':
          readdata = {};

          keyandchrs = read_until(data, dataoffset, ':');
          chrs = keyandchrs[0];
          keys = keyandchrs[1];
          dataoffset += chrs + 2;

          length = parseInt(keys, 10);
          contig = true;

          for (i = 0; i < length; i++) {
            kprops = _unserialize(data, dataoffset);
            kchrs = kprops[1];
            key = kprops[2];
            dataoffset += kchrs;

            vprops = _unserialize(data, dataoffset);
            vchrs = vprops[1];
            value = vprops[2];
            dataoffset += vchrs;

            if (key !== i)
              contig = false;

            readdata[key] = value;
          }
          
          if (contig) {
            array = new Array(length);
            for (i = 0; i < length; i++)
              array[i] = readdata[i];
            readdata = array;
          }

          dataoffset += 1;
          break;
        default:
          error('SyntaxError', 'Unknown / Unhandled data type(s): ' + dtype);
          break;
      }
      return [dtype, dataoffset - offset, typeconvert(readdata)];
    }
  ;

  return _unserialize((data + ''), 0)[2];
}
{% endcodeblock %}

 - [Raw function on GitHub](https://github.com/kvz/phpjs/blob/master/functions/var/unserialize.js)

Please note that php.js uses JavaScript objects as substitutes for PHP arrays, they are 
the closest match to this hashtable-like data structure. 

Please also note that php.js offers community built functions and goes by the 
[McDonald's Theory](https://medium.com/what-i-learned-building/9216e1c9da7d). We'll put online 
functions that are far from perfect, in the hopes to spark better contributions. 
Do you have one? Then please just: 

 - [Edit on GitHub](https://github.com/kvz/phpjs/edit/master/functions/var/unserialize.js)

### Example 1
This code
{% codeblock lang:js example %}
unserialize('a:3:{i:0;s:5:"Kevin";i:1;s:3:"van";i:2;s:9:"Zonneveld";}');
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
['Kevin', 'van', 'Zonneveld']
{% endcodeblock %}

### Example 2
This code
{% codeblock lang:js example %}
unserialize('a:3:{s:9:"firstName";s:5:"Kevin";s:7:"midName";s:3:"van";s:7:"surName";s:9:"Zonneveld";}');
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
{firstName: 'Kevin', midName: 'van', surName: 'Zonneveld'}
{% endcodeblock %}


### Other PHP functions in the var extension
{% render_partial _includes/custom/var.html %}