Encode an object's type as a numeric value.

encode.js

// encode.js MIT License © 2014 James Abney http://github.com/jabney

// Encode built-in type as a numeric value.
//
// typeOf(null);      // => 'Null'
// typeOf(undefined); // => 'Undefined'
// typeOf([]);        // => 'Array'
//
// encodeType(null);      // => 1
// encodeType(undefined); // => 2
// encodeType(1);         // => 3
// encodeType([]);        // => 4
//
// Encode an object's type as a number.
encodeType = (function() {
  var types = {
    'Null':      1,
    'Undefined': 2,
    'Number':    3,
    'Array':     4,
    'String':    5,
    'Object':    6,
    'Boolean':   7,
    'Function':  8,
    'Symbol':    9,
    'Date':      10,
    'Error':     11,
    'RegExp':    12,
    'Arguments': 13,
    'Math':      14,
    'JSON':      15
  };

  // Return a type code.
  function get(type) {
    // Return 0 for undefined types.
    return types[type] || 0;
  }

  // Return a numeric code corresponding to an object's type.
  return function encodeType(obj) {
    return get(typeOf(obj));
  }
})();