How Do I Handle Newlines in Json?

Question

I've generated some JSON and I'm trying to pull it into an object in JavaScript. I keep getting errors. Here's what I have:

var data = '{"count" : 1, "stack" : "sometext\n\n"}';
var dataObj = eval('('+data+')');

This gives me an error:

unterminated string literal

With JSON.parse(data), I see similar error messages: "Unexpected token ↵" in Chrome, and "unterminated string literal" in Firefox and IE.

When I take out the \n after sometext the error goes away in both cases. I can't seem to figure out why the \n makes eval and JSON.parse fail.

Accepted Answer

This is what you want:

var data = '{"count" : 1, "stack" : "sometext\\n\\n"}';

You need to escape the \ in your string (turning it into a double-\), otherwise it will become a newline in the JSON source, not the JSON data.

Answer 2

You will need to have a function which replaces \n to \\n in case data is not a string literal.

function jsonEscape(str)  {
    return str.replace(/\n/g, "\\\\n").replace(/\r/g, "\\\\r").replace(/\t/g, "\\\\t");
}

var data = '{"count" : 1, "stack" : "sometext\n\n"}';
var dataObj = JSON.parse(jsonEscape(data));

Resulting dataObj will be

Object {count: 1, stack: "sometext\n\n"}

Answer 3

TLDR: A solution to the author's problem.

Use String.raw literal:

var data = String.raw`{"count" : 1, "stack" : "sometext\n\n"}`;

For some reason all answers inside here focus on how to parse a JSON string representation in JavaScript, which may cause confusion regarding how to represent newlines on actual JSON. The latter is not language-dependent.

Strictly based on the question title :

Must Read

How do I handle newlines in JSON?

Let's say you parse a JSON file using the following code in node (it could be any language though):


let obj = JSON.parse(fs.readFileSync('file.json'));
console.log(obj.mykey)

Below is the output for each of the possible contents of file.json:

Input 1:

{
  "mykey": "my multiline
   value"
}

Output 1:

SyntaxError: Unexpected token

Input 2:

{
  "mykey": "my multiline\nvalue"
}

Output 2:

my multiline
value

Input 3:

{
  "mykey": "my multiline\\nvalue"
}

Output 3:

my multiline\nvalue

Conclusion 1:

To represent a newline inside a json file we should use the \n character. To represent the \n we should use \\n.

How Do I Handle Newlines in Json?

10 Answers

Must Read

How do I handle newlines in JSON?

Conclusion 1:

Alexander Ross