getting json from string - javascript

I have the following json object
"phrase": "{subject: Hello}"
When I access "phrase" it returns "{subject: Hello}" as a string but I want this string to be converted to json object.

There is a function called JSON.parse to convert things from strings to objects but I am not sure it would apply to your case, since you have invalid JSON (the "Hello" not being quoted is a bid deal and the "subject" not being quoted is a bad sign)

If it's a Javascript object literal, just remove the quotation marks when you create it:
var phrase = { subject: "Hello" };
If it's a JSON string that is parsed, change the string to an object:
{ "phrase": { "subject": "Hello" } }
If you have a variable that contains a JSON string, you need to make it valid JSON to parse it:
var phrase = '{ "subject": "Hello" }';
var obj = JSON.parse(phrase);
You can also parse the string as Javascript, which has a more relaxed syntax. The string value needs delimiters though:
var phrase = '{ subject: "Hello" }';
var obj = eval(phrase);
Note that the eval function actually executes the string as javascript, so you need to know where the string value comes from for this to be safe.

Use JSON.parse():
var obj = {myObj:"{\"this\":\"that\"}"};
obj.myObj = JSON.parse(obj.myObj);
alert(obj.myObj["this"]);
Here is the demo.

you could use native JSON parsing with JSON.parse(jsonString);
(Edit: assuming to have a valid JSON object)

Related

How to make string campatible for JSON.parse()

In my application when I enter value as my"name in text field the framework makes a String like (this i can not control):
"[{\"id\":\"201500000001002\",\"name\":\"my\"name\",\"colorCode\":\"\",\"version\":\"11\",\"nodeOrder\":\"1\"}]"
Now this String is passed to JSON.parse() method which produces an error because of ambiguous name field as
\"name\":\"my\"name\"
var str = JSON.parse("[{\"id\":\"201500000001002\",\"name\":\"my\"name\",\"colorCode\":\"\",\"version\":\"11\",\"nodeOrder\":\"1\"}]")
This results in JSON exception
Is there anything I can do with the string:
"[{\"id\":\"201500000001002\",\"name\":\"my\"name\",\"colorCode\":\"\",\"version\":\"11\",\"nodeOrder\":\"1\"}]"
To escape double quote character in my " name as my \" name to make it valid for JSON.parse method.
I can not control JSON String, I am just passing name as my"name and framework creates a String which is passed to JSON.parse()
I went through a series of text replace. You can try this:
var str = "[{\"id\":\"201500000001002\",\"name\":\"my\"name\",\"colorCode\":\"\",\"version\":\"11\",\"nodeOrder\":\"1\"}]";
JSON.parse(
str.replace(/\\/i,"").
replace(/{"/g,"{'").
replace(/":"/g,"':'").
replace(/","/g,"','").
replace(/"}/g,"'}").
replace(/'/g,"\###").
replace(/"/g,"\\\"").
replace(/###/g,"\"")
);
It will give back your desired JSON array
var str = "[{\"id\":\"201500000001002\"}]";
str.replace("\"*","\\\"");
var obj = JSON.parse(str);

How to convert a string value to Json

I receive a string in the format given below (with double quotes around it):
"'{ "param" : "value"}'"
How can I convert this string into json object so that I could use it as
alert(obj.param)
Thank you
Edit
As I mentioned in above the string has double quotes around it. Here is an example of how I get this string
CSHTML
#{
var prop = "{ \"param\" : \"value\"}";
<a data-type="#prop"></a>
}
and in JS I have this
var obj = anchor.data('type');
I want to be able to use obj.param, how do I achieve this?
Thanks
Use JSON.parse it parses a string as a JSON
var obj = JSON.parse(json);

convert invalid JSON string to JSON

I have an invalid json string like following,
"{one: 'one', two: 'two'}"
I tried to use JSON.parse to convert it to an object. however, this is not valid json string.
Is there any functions can convert this invalid format into a valid json string or directly convert into an object?
IF your example syntax is the same as your real JSON, JSONLint says you need double quote for the name AND the value.
In this case only, use these replace calls:
var jsontemp = yourjson.replace((/([\w]+)(:)/g), "\"$1\"$2");
var correctjson = jsontemp.replace((/'/g), "\"");
//yourjson = "{one: 'one', two: 'two'}"
//jsontemp = "{"one": 'one', "two": 'two'}"
//correctjson = "{"one": "one", "two": "two"}"
However you should try to work with a valid Json in the first place.
If the question is "can I convert invalid JSON into valid JSON", in the general case the answer is obviously "no"; where would you even start with a string like "$#!~~"?
In this particular case, the JSON is only invalid because the property names are not quoted; as JavaScript, the string is valid and could be parsed using, for example,
var myObj = eval( "x=" + myString );
or better
var myObj = (new Function("return " + myString))();
However, this is potentially very unsafe and you should not do it unless you are positive the string cannot cause harm (which seems unlikely if you aren't in a position to generate valid JSON in the first place). It also won't help you if the JSON code is invalid in other ways, and it will fail if the property names are not valid JS identifiers.
For a proper answer it would be useful to know more about the context of this question.

Parse JSON like string by javascript

I have this variable which is json-like string, error appear while parse to a object
"SyntaxError: JSON.parse: expected ',' or '}' after property value in object"
Code:
var obj = JSON.parse('{"data":[{"from":"{\"category\":\"Bank/financial institution\"}"}],"statusCode":200}');
Seems the function not available for nested "{\"category\":\"Bank/financial institution\"}", replace with simple text (e.g. "123") would be fine, is there any way to handle such cases? Thanks.
The \ (backslash) character before "category is unnecessary.
There's no need to escape a double quote in a single-quoted string.
Your string is indeed malformed.
You either want:
var obj = JSON.parse('{"data":[{"from":{"category":"Bank/financial institution"}}],"statusCode":200}');
...(e.g., without quotes around the value of from and without backslashes) which when deserialized results in an object with a property called data which is an array, which has as its first entry an object with a property called from which is an object: Live Example | Source
or
var obj = JSON.parse('{"data":[{"from":"{\\"category\\":\\"Bank/financial institution\\"}"}],"statusCode":200}');
...(e.g., keeping the quotes around the value for from and making sure the backslashes appear in the JSON, which means escaping them) which is the same until you get to from, which is a string: Live Example | Source
Remove quots for inner object
var obj = {
"data": [{
"from": {
"category": "Bank/financial institution"
}
}],
"statusCode": 200
}

JSON.stringify escaping without need

JSON.stringify is converting my json object to the following string
{\"2003\":{\"1\":{\"2\":[\"test\"],\"3\":[\"test2\"]}}}
When it should not be escaped. The result should be as the string quoted below
{"2003":{"1":{"2":["test"],"3":["test2"]}}}
Rather than use a general replace of all the escaped quotes and remove ones that could be in the input. How can I set JSON.stringify to not double escape the variables?
You are stringifying a string, not an object:
var str = '{"2003":{"1":{"2":["test"],"3":["test2"]}}}';
var obj = {"2003":{"1":{"2":["test"],"3":["test2"]}}};
console.log( JSON.stringify(str) ); // {\"2003\":{\"1\":{\"2\":[\"test\"],\"3\":[\"test2\"]}}}
console.log( JSON.stringify(obj) ); // {"2003":{"1":{"2":["test"],"3":["test2"]}}}
Try these two examples in browser`s console:
let obj = {2003:{1:{2:["test"],3:["test2"]}}};
JSON.stringify(obj);
-> "{\"2003\":{\"1\":{\"2\":[\"test\"],\"3\":[\"test2\"]}}}"
and
let obj = {2003:{1:{2:["test"],3:["test2"]}}};
console.log(JSON.stringify(obj));
-> {"2003":{"1":{"2":["test"],"3":["test2"]}}}
In both cases the string returned from JSON.stringify is valid
In the first case you print "raw" string to console which starts and ends with double quote and all nested double quotes need to be escaped (\" instead of "). JSON validators will mark this string as malformed JSON but it is still parsable with JSON.parse
In the second case you print string "interpreted" as JSON by console.log. JSON validators will mark it as valid JSON but it is no parsable with JSON.parse because it is not string (no quotes around)

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