处理JSON的有效工具类

jquery插件
(function ($) {
    var m = {
            '\b': '\\b',
            '\t': '\\t',
            '\n': '\\n',
            '\f': '\\f',
            '\r': '\\r',
            '"' : '\\"',
            '\\': '\\\\'
        },
        s = {
            'array': function (x) {
                var a = ['['], b, f, i, l = x.length, v;
                for (i = 0; i < l; i += 1) {
                    v = x[i];
                    f = s[typeof v];
                    if (f) {
                        v = f(v);
                        if (typeof v == 'string') {
                            if (b) {
                                a[a.length] = ',';
                            }
                            a[a.length] = v;
                            b = true;
                        }
                    }
                }
                a[a.length] = ']';
                return a.join('');
            },
            'boolean': function (x) {
                return String(x);
            },
            'null': function (x) {
                return "null";
            },
            'number': function (x) {
                return isFinite(x) ? String(x) : 'null';
            },
            'object': function (x) {
                if (x) {
                    if (x instanceof Array) {
                        return s.array(x);
                    }
                    var a = ['{'], b, f, i, v;
                    for (i in x) {
                        v = x[i];
                        f = s[typeof v];
                        if (f) {
                            v = f(v);
                            if (typeof v == 'string') {
                                if (b) {
                                    a[a.length] = ',';
                                }
                                a.push(s.string(i), ':', v);
                                b = true;
                            }
                        }
                    }
                    a[a.length] = '}';
                    return a.join('');
                }
                return 'null';
            },
            'string': function (x) {
                if (/["\\\x00-\x1f]/.test(x)) {
                    x = x.replace(/([\x00-\x1f\\"])/g, function(a, b) {
                        var c = m[b];
                        if (c) {
                            return c;
                        }
                        c = b.charCodeAt();
                        return '\\u00' +
                            Math.floor(c / 16).toString(16) +
                            (c % 16).toString(16);
                    });
                }
                return '"' + x + '"';
            }
        };

	$.toJSON = function(v) {
		var f = isNaN(v) ? s[typeof v] : s['number'];
		if (f) return f(v);
	};
	
	$.parseJSON = function(v, safe) {
		if (safe === undefined) safe = $.parseJSON.safe;
		if (safe && !/^("(\\.|[^"\\\n\r])*?"|[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t])+?$/.test(v))
			return undefined;
		return eval('('+v+')');
	};
	
	$.parseJSON.safe = false;

})(jQuery);

 原生js

if (typeof JSON !== 'object') {
    JSON = {};
}

(function() {
    'use strict';

    function f(n) {
        return n < 10 ? '0' + n : n;
    }

    if (typeof Date.prototype.toJSON !== 'function') {

        Date.prototype.toJSON = function(key) {

            return isFinite(this.valueOf()) ? this.getUTCFullYear() + '-' + f(this.getUTCMonth() + 1) + '-' + f(this.getUTCDate()) + 'T' + f(this.getUTCHours()) + ':' + f(this.getUTCMinutes()) + ':' + f(this.getUTCSeconds()) + 'Z' : null;
        };

        String.prototype.toJSON = Number.prototype.toJSON = Boolean.prototype.toJSON = function(
        key) {
            return this.valueOf();
        };
    }

    var cx = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
        escapable = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
        gap, indent, meta = { // table of character substitutions
            '\b': '\\b',
            '\t': '\\t',
            '\n': '\\n',
            '\f': '\\f',
            '\r': '\\r',
            '"': '\\"',
            '\\': '\\\\'
        },
        rep;

    function quote(string) {

        escapable.lastIndex = 0;
        return escapable.test(string) ? '"' + string.replace(escapable, function(a) {
            var c = meta[a];
            return typeof c === 'string' ? c : '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
        }) + '"' : '"' + string + '"';
    }

    function str(key, holder) {

        var i, // The loop counter.
        k, // The member key.
        v, // The member value.
        length, mind = gap,
            partial, value = holder[key];

        if (value && typeof value === 'object' && typeof value.toJSON === 'function') {
            value = value.toJSON(key);
        }

        if (typeof rep === 'function') {
            value = rep.call(holder, key, value);
        }

        switch (typeof value) {
        case 'string':
            return quote(value);

        case 'number':

            return isFinite(value) ? String(value) : 'null';

        case 'boolean':
        case 'null':

            return String(value);

        case 'object':

            if (!value) {
                return 'null';
            }

            gap += indent;
            partial = [];

            if (Object.prototype.toString.apply(value) === '[object Array]') {

                length = value.length;
                for (i = 0; i < length; i += 1) {
                    partial[i] = str(i, value) || 'null';
                }

                v = partial.length === 0 ? '[]' : gap ? '[\n' + gap + partial.join(',\n' + gap) + '\n' + mind + ']' : '[' + partial.join(',') + ']';
                gap = mind;
                return v;
            }

            if (rep && typeof rep === 'object') {
                length = rep.length;
                for (i = 0; i < length; i += 1) {
                    if (typeof rep[i] === 'string') {
                        k = rep[i];
                        v = str(k, value);
                        if (v) {
                            partial.push(quote(k) + (gap ? ': ' : ':') + v);
                        }
                    }
                }
            } else {

                for (k in value) {
                    if (Object.prototype.hasOwnProperty.call(value, k)) {
                        v = str(k, value);
                        if (v) {
                            partial.push(quote(k) + (gap ? ': ' : ':') + v);
                        }
                    }
                }
            }

            v = partial.length === 0 ? '{}' : gap ? '{\n' + gap + partial.join(',\n' + gap) + '\n' + mind + '}' : '{' + partial.join(',') + '}';
            gap = mind;
            return v;
        }
    }

    if (typeof JSON.stringify !== 'function') {
        JSON.stringify = function(value, replacer, space) {

            var i;
            gap = '';
            indent = '';

            if (typeof space === 'number') {
                for (i = 0; i < space; i += 1) {
                    indent += ' ';
                }

            } else if (typeof space === 'string') {
                indent = space;
            }

            rep = replacer;
            if (replacer && typeof replacer !== 'function' && (typeof replacer !== 'object' || typeof replacer.length !== 'number')) {
                throw new Error('JSON.stringify');
            }

            return str('', {
                '': value
            });
        };
    }

    if (typeof JSON.parse !== 'function') {
        JSON.parse = function(text, reviver) {

            var j;

            function walk(holder, key) {

                var k, v, value = holder[key];
                if (value && typeof value === 'object') {
                    for (k in value) {
                        if (Object.prototype.hasOwnProperty.call(value, k)) {
                            v = walk(value, k);
                            if (v !== undefined) {
                                value[k] = v;
                            } else {
                                delete value[k];
                            }
                        }
                    }
                }
                return reviver.call(holder, key, value);
            }

            text = String(text);
            cx.lastIndex = 0;
            if (cx.test(text)) {
                text = text.replace(cx, function(a) {
                    return '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
                });
           

 }

            if (/^[\],:{}\s]*$/.test(text.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g, '@').replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']').replace(/(?:^|:|,)(?:\s*\[)+/g, ''))) {

                j = eval('(' + text + ')');

                return typeof reviver === 'function' ? walk({
                    '': j
                }, '') : j;
            }

            throw new SyntaxError('JSON.parse');
        };
    }
}());