Develop Reference

why JSON.parse does not convert a string to json object?

I tried to convert a string to a javascript object using JSON.parse but it's not working.
I tried everything but did not get anything on the console.log and there is no error message.
JSON.parse(`{'exp': '1', 'input': '1d6404f66ed3d72e', 'iterate': 'no'}`);
Update
In the real code, I'm passing the value from an object
console.log(JSON.parse(future.onIOPub.data['text/plain']))

When you run this, you should see
Uncaught SyntaxError: Unexpected token ' in JSON at position 1
This error is because you are using single quotes. JSON only accepts double quotes, as described in the spec
https://www.json.org/json-en.html

JSON Parse with square brackets inside data

I am trying to parse a JSON string which contains square brackets inside the string.
For example
"[[\"hello\", \"i\", \"like [cows]\"], [\"what\", \"about [you]?\"]]"
It shows an error while parsing:
Uncaught SyntaxError: Unexpected token [
How can I parse the string anyway while leaving the brackets as they are?

I found the problem. I needed to use addslashes() around the strings in the PHP code which serves the code. There was a part of a string containing [C:\].

I see in your later comments that you're creating this JSON string within PHP. You should encode the JSON data within PHP using json_encode, as shown here:
http://www.dyn-web.com/tutorials/php-js/json/array.php
It should then come out in a format that you can JSON.parse.

Unexpected Token while Parsing JSON

This is fraustating me for 5 hours and now i have to finally ask this question.
I am trying to parse JSON using Javascript, but i don't know why i am getting this error on Console:
Uncaught SyntaxError: Unexpected token (…)
(anonymous function) # VM382:2InjectedScript._evaluateOn #
VM251:904InjectedScript._evaluateAndWrap # VM251:837InjectedScript.evaluate
#VM251:693
JSON : http://pastebin.com/DddXQj6d
JS Code:
var json=**big json**;
var obj=JSON.parse(json);
Tried:
JSON.stringify(json);
json= "'" + json+ "'";
Loading JSON from URL

According to JSONLint and the Pastebin that you posted, the JSON is invalid, mostly due to the use of \'. Once you replace all of them by ', it should work normally.
In your original JSON file there are probably going to be some occurrences of \\'. As a string they become \'.
If you’re using Linux, a simple
sed -i "s/\\\\\\\'/\'/g" yourJSONFile.json
on your file fixes everything.
JSONLint says “Valid JSON” then.
You can also try
JSON.parse(json.replace(/\\'/,'\''));

Error parsing JSON data - "Uncaught SyntaxError: Unexpected token ."

I'm getting the error below in Chrome while parsing a JSON data. The data sample is at http://jsoneditoronline.org/?id=31ffc7c0e7e1a9a2adf641306497b57a This is a valid JSON and my server is sending the correct Content-Type value (application/json).
Uncaught SyntaxError: Unexpected token .
Firefox reports a slightly different message but it all points to the presence of the period (.) in the beginning of the content.
SyntaxError: JSON.parse: unexpected non-whitespace character after JSON data at line 1 column 6 of the JSON data
I've tried both $.parseJSON() and JSON.parse() methods.
What's the cause of this error? Please enlighten.
I've read the other similar posts here, but they refer to a different character like <, etc.,
EDIT: This is the piece of code I'm using to retrieve the server data.
$.ajax({
url : searchUrl
}).done(function(data) {
var json_array = JSON.parse(data); // Apparently data is already JSON parsed.
});

That data probably is already an object, try it without $.parseJSON() or JSON.parse() and it should work.

Parsing simple JSON using Ext gives SyntaxError: Unexpected token ILLEGAL

i'm doing a simple parse of some JSON and it's giving me an error in chrome, what am i missing here?
Ext.util.JSON.decode("{info: {synopsis: 'test'}}");
SyntaxError: Unexpected token ILLEGAL
Thanks a lot

http://www.json.org/
Think you should use double quotes instead of single quotes.
Ext.util.JSON.decode('{"info": {"synopsis": "test"}}');

Be careful if you are using ExtJs 4 onward, You have to use
Ext.JSON.decode('{"info": {"synopsis": "test"}}');