原文：jQuery方法扩展：type, toJSON, evalJSON. http://zhkac.iteye.com/blog/499330 .2013-05-19
(function($) {
// the code of this function is from
// http://lucassmith.name/pub/typeof.html
$.type = function(o) {
var _toS = Object.prototype.toString;
var _types = {
'undefined': 'undefined',
'number': 'number',
'boolean': 'boolean',
'string': 'string',
'[object Function]': 'function',
'[object RegExp]': 'regexp',
'[object Array]': 'array',
'[object Date]': 'date',
'[object Error]': 'error'
};
return _types[typeof o] || _types[_toS.call(o)] || (o ? 'object' : 'null');
};
// the code of these two functions is from mootools
// http://mootools.net
var $specialChars = { '\b': '\\b', '\t': '\\t', '\n': '\\n', '\f': '\\f', '\r': '\\r', '"': '\\"', '\\': '\\\\' };
var $replaceChars = function(chr) {
return $specialChars[chr] || '\\u00' + Math.floor(chr.charCodeAt() / 16).toString(16) + (chr.charCodeAt() % 16).toString(16);
};
$.toJSON = function(o) {
var s = [];
switch ($.type(o)) {
case 'undefined':
return 'undefined';
break;
case 'null':
return 'null';
break;
case 'number':
case 'boolean':
case 'date':
case 'function':
return o.toString();
break;
case 'string':
return '"' + o.replace(/[\x00-\x1f\\"]/g, $replaceChars) + '"';
break;
case 'array':
for (var i = 0, l = o.length; i < l; i++) {
s.push($.toJSON(o[i]));
}
return '[' + s.join(',') + ']';
break;
case 'error':
case 'object':
for (var p in o) {
s.push(p + ':' + $.toJSON(o[p]));
}
return '{' + s.join(',') + '}';
break;
default:
return '';
break;
}
};
$.evalJSON = function(s) {
if ($.type(s) != 'string' || !s.length) return null;
return eval('(' + s + ')');
};
})(jQuery);