Are multi-line strings allowed in JSON?

JSON does not allow real line-breaks. You need to replace all the line breaks with \n.

eg:

"first line second line"

can saved with:

"first line\nsecond line"

Note:

for Python, this should be written as:

"first line\\nsecond line"

where \\ is for escaping the backslash, otherwise python will treat \n as the control character "new line"

Unfortunately many of the answers here address the question of how to put a newline character in the string data. The question is how to make the code look nicer by splitting the string value across multiple lines of code. (And even the answers that recognize this provide "solutions" that assume one is free to change the data representation, which in many cases one is not.)

And the worse news is, there is no good answer.

In many programming languages, even if they don't explicitly support splitting strings across lines, you can still use string concatenation to get the desired effect; and as long as the compiler isn't awful this is fine.

But json is not a programming language; it's just a data representation. You can't tell it to concatenate strings. Nor does its (fairly small) grammar include any facility for representing a string on multiple lines.

Short of devising a pre-processor of some kind (and I, for one, don't feel like effectively making up my own language to solve this issue), there isn't a general solution to this problem. IF you can change the data format, then you can substitute an array of strings. Otherwise, this is one of the numerous ways that json isn't designed for human-readability.

I have had to do this for a small Node.js project and found this work-around:

{
 "modify_head": [

  "<script type='text/javascript'>",
  "<!--",
  "  function drawSomeText(id) {",
  "  var pjs = Processing.getInstanceById(id);",
  "  var text = document.getElementById('inputtext').value;",
  "  pjs.drawText(text);}",
  "-->",
  "</script>"

 ],

 "modify_body": [

  "<input type='text' id='inputtext'></input>",
  "<button onclick=drawSomeText('ExampleCanvas')></button>"

 ],
}

This looks quite neat to me, appart from that I have to use double quotes everywhere. Though otherwise, I could, perhaps, use YAML, but that has other pitfalls and is not supported natively. Once parsed, I just use myData.modify_head.join('\n') or myData.modify_head.join(), depending upon whether I want a line break after each string or not.

Check out the specification! The JSON grammar's char production can take the following values:

• any-Unicode-character-except-"-or-\-or-control-character
• \"
• \\
• \/
• \b
• \f
• \n
• \r
• \t
• \u four-hex-digits

Newlines are "control characters" so, no, you may not have a literal newline within your string. However you may encode it using whatever combination of \n and \r you require.

JSON doesn't allow breaking lines for readability.

Your best bet is to use an IDE that will line-wrap for you.