JavaScript JSon string decode

Question

I have this string:

{\"description\": \"PSY - Gangnam Style (\\uac15\\ub0a8\\uc2a4\\ud0c0\\uc77c) \\n\\u25b6 NOW available on iTunes: http:\\\/\\\/Smarturl.it\\\/psygangnam\\n\\u25b6 Official PSY Online Store US \\u0026 International : http:\\\/\\\/psy.shop.bravadousa.com\\\/\\n\\u25b6 About PSY from YG Ent.: http:\\\/\\\/smarturl.it\\\/YGfamilyAboutPSY\\n\\u25b6 PSY's Products on eBay: http:\\\/\\\/stores.ebay.com\\\/ygentertainment\\n\\u25b6 YG-eShop: http:\\\/\\\/www.ygeshop.com\\n \\n===============================\\nPSY CONCERT \\\"HAPPENING\\\"\\n2013.4.13. SAT 6:30PM\\nTHE SEOUL WORLD CUP STADIUM\\nYouTube LIVE@ http:\\\/\\\/www.youtube.com\\\/officialpsy\\nTickets: http:\\\/\\\/smarturl.it\\\/PsyHappeningKor\\nEnglish Booking: http:\\\/\\\/smarturl.it\\\/PsyHappeningEng\\n===============================\\n\\nFor More Information @\\nhttp:\\\/\\\/www.facebook.com\\\/officialpsy\\nhttp:\\\/\\\/twitter.com\\\/psy_oppa\\nhttp:\\\/\\\/twitter.com\\\/ygent_official\\nhttp:\\\/\\\/me2day.net\\\/psyfive\\nhttp:\\\/\\\/www.psypark.com\\nApp Store: http:\\\/\\\/goo.gl\\\/l9TU6\\nGoogle Play: http:\\\/\\\/goo.gl\\\/UiEn1\\n\\n\\u00a9 YG Entertainment Inc. All rights reserved.\"}

And i want to parse it with Json and it's fail. i try to convert the \" with " with :

tmp = tmp.replace(/\\"/gi, '"');

And it change it to :

{"description": "PSY - Gangnam Style (\\uac15\\ub0a8\\uc2a4\\ud0c0\\uc77c) \\n\\u25b6 NOW available on iTunes: http:\\\/\\\/Smarturl.it\\\/psygangnam\\n\\u25b6 Official PSY Online Store US \\u0026 International : http:\\\/\\\/psy.shop.bravadousa.com\\\/\\n\\u25b6 About PSY from YG Ent.: http:\\\/\\\/smarturl.it\\\/YGfamilyAboutPSY\\n\\u25b6 PSY's Products on eBay: http:\\\/\\\/stores.ebay.com\\\/ygentertainment\\n\\u25b6 YG-eShop: http:\\\/\\\/www.ygeshop.com\\n \\n===============================\\nPSY CONCERT \\"HAPPENING\\"\\n2013.4.13. SAT 6:30PM\\nTHE SEOUL WORLD CUP STADIUM\\nYouTube LIVE@ http:\\\/\\\/www.youtube.com\\\/officialpsy\\nTickets: http:\\\/\\\/smarturl.it\\\/PsyHappeningKor\\nEnglish Booking: http:\\\/\\\/smarturl.it\\\/PsyHappeningEng\\n===============================\\n\\nFor More Information @\\nhttp:\\\/\\\/www.facebook.com\\\/officialpsy\\nhttp:\\\/\\\/twitter.com\\\/psy_oppa\\nhttp:\\\/\\\/twitter.com\\\/ygent_official\\nhttp:\\\/\\\/me2day.net\\\/psyfive\\nhttp:\\\/\\\/www.psypark.com\\nApp Store: http:\\\/\\\/goo.gl\\\/l9TU6\\nGoogle Play: http:\\\/\\\/goo.gl\\\/UiEn1\\n\\n\\u00a9 YG Entertainment Inc. All rights reserved."}

But here i get :

PSY CONCERT \\"HAPPENING\\"\\n2013.4.13. SAT 6:30PM

In one of the rows and i want to know if there is any decode method to decode the string to be valid for parse to json object?

I know the input is not legal and i want to know if there is any function to decode the string to valid json string — YosiFZ
– YosiFZ, Commented Jul 24, 2013 at 11:22
It look like you have to make sure that \\\" will be replaced with ', before you replace every \" with ". By the way, it would have been nice, you had narrowed your problem a little bit down and could just present a small sample string instead of this monster of a string. — basilikum
– basilikum, Commented Jul 24, 2013 at 11:28
It appears to be a string of JSON that was re-encoded as a JSON String. Perhaps try to patch the source so it only encodes once? Or, parse twice to match: JSON.parse(JSON.parse(tmp)). — Jonathan Lonowski
– Jonathan Lonowski, Commented Jul 24, 2013 at 11:30

Bergi · Accepted Answer · 2013-07-24 12:33:16Z

1

Your string seems to be double-escaped but missing its outer delimiters.

var str = '{\\"description\\": \\"PSY - Gangnam Style (\\\\uac15\\\\ub0a8\\\\uc2a4\\\\ud0c0\\\\uc77c) … .\\"}';
var jsonStr = JSON.parse('"'+str+'"'),
    obj = JSON.parse(jsonStr);

answered Jul 24, 2013 at 12:33

Bergi

671k162 gold badges1k silver badges1.5k bronze badges

Sign up to request clarification or add additional context in comments.

Comments

basilikum · Accepted Answer · 2013-07-24 12:10:04Z

It might be not the best solution, but evaluating your string before you parse it to JSON should work:

eval("tmp = \"" + tmp + "\";");
var tmpJSON = JSON.parse(tmp);

But keep in mind that you are evaluation a presumably unknown string, which is not really safe. Maybe there is a decoding function out there, that does the same.

So why should this work?

You string looks like a string, that I would write when I write a piece of code. It has all the escape backslashes that are needed to print a quote or a backslash itself. But those escape characters shouldn't be really inside the string, they are just there to define what the string should look like. So, writing var str = "He said \"ok\""; will produce a string like He said "ok". But since your string actually contains the escape characters, it would be defined like this instead:

var str = "He said \\\"ok\\\"";

which will produce a string like this:

He said \"ok\"

Now everything inside of eval is interpreted as a piece of code. So when I write:

eval("str = \"" + str + "\";");

the line of code that gets executed is:

str = "He said \"ok\"";

which results in the desired unescaped string:

He said "ok"

Community · Accepted Answer · 2017-05-23 12:21:36Z

0

Not as elegant as basilikum's approach, and likely also not as correct as the double-parsing approach that Bergi and Jonathan Lonowsky suggest, but you could use a Javascript negative lookbehind equivalent, along these lines:

str.replace(/\\+"/gi, function(s){return (s.length % 2) ? s : s.slice(0,-2) + '"';})

This is definitely more secure than evaluating the string.

edited May 23, 2017 at 12:21

CommunityBot

11 silver badge

answered Jul 24, 2013 at 11:56

Aryeh Leib Taurog

5,6561 gold badge45 silver badges51 bronze badges

Collectives™ on Stack Overflow

JavaScript JSon string decode

3 Answers 3

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related