Parsing all possible UTF-8 values in a json string - javascript

How can I get the following to run without the unexpected token error?
I would like to parse any possible utf-8 in a JSON string. Since characters like \u0000 (null) are valid UTF-8 I should be able to parse them in a json string right?
s='{"body": "\u0000"}'
JSON.parse(s)
SyntaxError: Unexpected token in JSON at position 10
I get the same error using JSON.parse(unescape(encodeURIComponent(s))).
Here is a larger sample from the data set:
\u0000\u0001\u0002\u0003\u0004\u0005\u0006\a\b\t\n
!\"#$%&'()*+,-./0123456789:;<=>?
ΣΤΥΦΧΨΩΪΫάέήίΰαβγδεζηθικλμνξοπρςστυφχψωϊϋόύ

Use double reverse solidus and it's good to go. Such as:
s=`{"body": "\\u0000"}`
JSON.parse(s)
or
s=`{"body": "\\t"}`
JSON.parse(s)

Related

How can I resolve JSON parsing error 'JSON.parse: bad control character in string literal'?

In NodeJS Backend, I send my data to client as:-
res.end(filex.replace("<userdata>", JSON.stringify({name:user.name, uid:user._id, profile:user.profile}) ))
//No error here and Object is stringified perfectly
//user is object returned in mongoDB's result
The JSON string looks like this:
{"name":"Rishavolva","uid":"5f3ce234fd83024334050872","profile":{"pic":{"small_link":"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyZXBsaWNhcyI6MiwidXJpcyI6W3siZGJfbmFtZSI6ImlmcmRiMDAxIiwidGFibGUiOiJGSUxFIiwiaWQiOjQ4fSx7ImRiX25hbWUiOiJpZnJkYjAwMiIsInRhYmxlIjoiRklMRSIsImlkIjo0OH1dLCJ1aWRfd2hpdGVsaXN0IjoiKiIsImlhdCI6MTU5ODE2MzMzNX0.9NkGnEumn4JW8IN0KFgxgN_6_4wN8qOgezNTyzz9osY","big_link":"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyZXBsaWNhcyI6MiwidXJpcyI6W3siZGJfbmFtZSI6ImlmcmRiMDAxIiwidGFibGUiOiJGSUxFIiwiaWQiOjQ3fSx7ImRiX25hbWUiOiJpZnJkYjAwMiIsInRhYmxlIjoiRklMRSIsImlkIjo0N31dLCJ1aWRfd2hpdGVsaXN0IjoiKiIsImlhdCI6MTU5ODE2MzMzNX0.yxQ1GrhLsWPn8Qwu42EfTDXqaYwFtrM6f_7cAH2eLRY"},"aboutme":"I am Rishav Bhowmik\r\nand this is navratna pulaow"}}
and that UID is just a mongodb's primary key as string, and other two base 64 strings are just JWT tokens.
Now, when this JSON string reaches the Browser, I parse it with simple:
JSON.parse(`<userdata>`)
//remember I used filex.replace("<userdata>", JSON.stringify...) in the server
For reference, my MongoDB Document here is:
Now when JSON.parse is executed on the JSON string it will look like this on final JS code.
JSON.parse(`{"name":"Rishavolva","uid":"5f3ce234fd83024334050872","profile":{"pic":{"small_link":"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyZXBsaWNhcyI6MiwidXJpcyI6W3siZGJfbmFtZSI6ImlmcmRiMDAxIiwidGFibGUiOiJGSUxFIiwiaWQiOjQ4fSx7ImRiX25hbWUiOiJpZnJkYjAwMiIsInRhYmxlIjoiRklMRSIsImlkIjo0OH1dLCJ1aWRfd2hpdGVsaXN0IjoiKiIsImlhdCI6MTU5ODE2MzMzNX0.9NkGnEumn4JW8IN0KFgxgN_6_4wN8qOgezNTyzz9osY","big_link":"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJyZXBsaWNhcyI6MiwidXJpcyI6W3siZGJfbmFtZSI6ImlmcmRiMDAxIiwidGFibGUiOiJGSUxFIiwiaWQiOjQ3fSx7ImRiX25hbWUiOiJpZnJkYjAwMiIsInRhYmxlIjoiRklMRSIsImlkIjo0N31dLCJ1aWRfd2hpdGVsaXN0IjoiKiIsImlhdCI6MTU5ODE2MzMzNX0.yxQ1GrhLsWPn8Qwu42EfTDXqaYwFtrM6f_7cAH2eLRY"},"aboutme":"I am Rishav Bhowmik\r\nand this is navratna pulaow"}}`)
I get this error:
Uncaught SyntaxError: JSON.parse: bad control character in string literal at line 1 column 702 of the JSON data
the string at position 702 of the JSON string is \n
First of all, how can \n be a control character?
What should I do to resolve this?
Has this problem arrised due to MONGODB result?
\n is a control character signifying a new line. In JSON, those control characters (more specifically the \) must be escaped inside strings.
This will raise the error:
JSON.parse(`{"hello":"world\n"}`)
This wont:
JSON.parse(`{"hello":"world\\n"}`)
So one way would be to use something like replace to ensure your aboutme is properly escaped before JSON serialization. See: How to escape a JSON string containing newline characters using JavaScript?
Ok have done some experimentation and have a solution.
The Trick is to do JSON.stringify() twice,
Like,
html_text.replace('/*<whatever>*/', JSON.stringify( JSON.stringify(the_object) ) )
If suppose html_text has a line which is
<script>
const object_inbrowser = JSON.parse(/*<whatever>*/)
// no need to add qotes, `JSON.stringify` in the server will do that for you
</script>

Unexpected Token in string version of valid JSON while performing JSON.parse

I am having problem converting a JSON String into Javascript object.
I ran into a few suggestions which said that I should not be using multi-line string but using single line string too did not work.
Snippet: https://jsfiddle.net/ankschoubey/hjh2d3z6/
SyntaxError: Unexpected token F in JSON at position 4536
Because you're including JSON as a JavaScript string value, you'll have to double-up on all the embedded backslash characters because they'll be parsed twice: first when the JavaScript parser reads the overall string constant to create the string value, and then again when you call JSON.parse().
Thus that portion of the string with \" should be \\". That way, the JavaScript string parsing will turn \\" into just \", and that's what will make the JSON parser happy.

parse json string with forward slashes - javascript

Looks pretty simple but I am unable to figure it out
var str="[{name:\"House\",id:\"1\"},{name:\"House and Land\",id:\"5\"},{name:\"Land\",id:\"6\"},{name:\"Terrace\",id:\"11\"}]";
JSON.parse(str.replace(/\s/g, "").replace(/\//g, ''));
I am unable to the convert above string(which comes from 3rd party website) to valid json so that I can iterate it on my side
error
VM5304:1 Uncaught SyntaxError: Unexpected token n in JSON at position 2
at JSON.parse (<anonymous>)
JSON requires the keys to be quoted. It appears that your keys are coming in unquoted. So add another .replace statement to insert the quote back in:
.replace(/(\w+):/g, '"$1":');
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON
Property names must be double-quoted strings; trailing commas are forbidden.
COMPLETE SOLUTION:
.replace(/(,|{)\s*(\w+)\s*:/g, '$1"$2":');

Uncaught SyntaxError: Unexpected token ' in JSON at position 2

I've an encoded stringifyed JSON object stored in database, I decoded it and loaded it and tried to parse it into an object But I get
Uncaught SyntaxError: Unexpected token ' in JSON at position 2
at JSON.parse ()
Code:
var attr = new Object();
attr = JSON.parse(code[1].replace(/"/g, "'"));
Object decoded:
[{'inputs':0,'type':'variable'},{'inputD':0,'type':'variable'},{'inputI':0,'type':'variable'},{'paras':0,'type':'variable'},{'headers':0,'type':'variable'},{'menus':0,'type':'variable'},{'lists':0,'type':'variable'},{'divs':0,'type':'variable'},{'links':0,'type':'variable'},{'images':0,'type':'variable'},{'elemName':'{}','type':'object'},{'borders':[],'type':'array'},{'nested':[],'type':'array'},{'ribbons':[],'type':'array'},{'tooltips':[],'type':'array'},{'gradColors':'{}','type':'object'},{'events':'{}','type':'object'},{'sTarget':'{}','type':'object'},{'sMain':'{}','type':'object'},{'orignalStyle':'{}','type':'object'},{'objNewStyle':'{}','type':'object'},{'functions':'{}','type':'object'},{'reverse':'{}','type':'object'},{'reverseFunction':'{}','type':'object'},{'scDetails':'{}','type':'object'}]
I have same error, #Philipp Zitzmann is correct.
You must valid json string at https://jsonformatter.curiousconcept.com/
valid json string must have double quote.
JSON.parse({"u1":1000,"u2":1100}) // will be ok
no quote cause error
JSON.parse({u1:1000,u2:1100})
// error Uncaught SyntaxError: Unexpected token u in JSON at position 2
single quote cause error
JSON.parse({'u1':1000,'u2':1100})
// error Uncaught SyntaxError: Unexpected token u in JSON at position 2
JSON should be wrapped in double quotes like:
{"inputs":0,"type":"variable"}
This is a useful Tool for validating:
https://jsonformatter.curiousconcept.com/
This is not valid json string. Its values and keys should be surrounded with double quotes (not single). So when you do .replace(/"/g, "'") you basically break the JSON standard.
A value can be a string in double quotes, or a number, or true or
false or null, or an object or an array. These structures can be
nested.
A related one. Today I hit the same error. An example is below:
Correct
JSON.parse( "[1,2,3,4,5,6,7,8,9,0]" )
Incorrect
JSON.parse( "[1,2,3,4,5,6,7,8,..." )
Note the 3 dots (...), because a tool showed only few numbers in array, and gave ... for rest.
In other words, string passed to JSON.parse() is invalid, so it gave error.
But it can be any other similar error.
For example, (may be) JSON.parse( "true" ) is correct but JSON.parse( "tr" ) fails, etc.

Unexpected error while parsing JSON in javascript

I am getting a string object after splitting from a text. Now I am trying to convert that text to a JSON object.
Text after Splitting
{location:"Web",initial:"",firmType:"",toaxfrtype:""}
When I am trying to parse it using JSON.parse, I am getting an error,
SyntaxError: Unexpected token l.
I have some other string value as the same in the above text. It was parsing fine using JSON.parse. Only the above string is not working.
Can anybody help me in this issue.
You need quotes " so change
{location:"Web",initial:"",firmType:"",toaxfrtype:""}
to
{"location":"Web","initial":"","firmType":"","toaxfrtype":""}
I have attached the image where it says valid now after correction. You can online validators to validate it first.
This is not JSON. You need to quote all Strings, including the keys.

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