JSON returned from Response.json() appears to be invalid?-CodePudding

Checking the JSON output of my application on https://jsonlint.com/ indicates that the JSON is invalid... But I cannot fathom how it's invalid.

The JSON in question:

{
    records: [{
        id: 70,
        whse: '00',
        partNo: '100E',
        description: '1" EMT CONDUIT (BUNDLE QTY. 1000FT)',
    }],
    start: 0,
    limit: 10,
    count: 1
}

I've tried changing the type of quotes used to no avail. The error returned doesn't really help me at all either:

Error: Parse error on line 1:
{   records: [{     id: 70
--^
Expecting 'STRING', '}', got 'undefined'

As far as I can tell, it's valid JSON. This JSON is being returned from a Response.json() function call after a successful fetch().

CodePudding user response：

You were right to think of the quotes as a potential source of problem.

That's a valid JavaScript Object yes. Meaning a JS interpreter will successfully understand it if you were to do:

const variable = {
    records: [{
        id: 70,
        whse: '00',
        partNo: '100E',
        description: '1" EMT CONDUIT (BUNDLE QTY. 1000FT)',
    }],
    start: 0,
    limit: 10,
    count: 1
};

but that's not a valid JSON string. if you want valid JSON string, you'd need to stringify it like this:

JSON.stringify({
    records: [{
        id: 70,
        whse: '00',
        partNo: '100E',
        description: '1" EMT CONDUIT (BUNDLE QTY. 1000FT)',
    }],
    start: 0,
    limit: 10,
    count: 1
});

and the result would be the string:

{
  "records": [
    {
      "id": 70,
      "whse": "00",
      "partNo": "100E",
      "description": "1\" EMT CONDUIT (BUNDLE QTY. 1000FT)"
    }
  ],
  "start": 0,
  "limit": 10,
  "count": 1
}

(notice the double quotes around key names)

CodePudding user response：

That is because raw JSON expects string or ints as property, however, for a javascript JSON its a valid syntax. There are several things that jsonlint didnt liked, in order to fix this you must

Add double quotes for each property
Change to double quotes for each string value
Remove the last comma of the object

And you will get something like this:

{
    "records": [{
        "id": 70,
        "whse": "00",
        "partNo": "100E",
        "description": "1\" EMT CONDUIT (BUNDLE QTY. 1000FT)"
    }],
    "start": 0,
    "limit": 10,
    "count": 1
}

Also, take into consideration that since you have double quotes inside a string you have to use the backslash to escape the character