How to call the JSON.stringify() function with space argument to generate JSON text strings indented with friendly spaces?

If you call JSON.stringify() without the "space" argument, the JSON text string will be generated in a single line, with no line breaks and space indentions.

If you want to break lines after each array element or object property, you need to the "space" argument in the JSON.stringify() call.

• If "space" is given as a number, successive levels in the stringification will each be indented by this many space characters.
• If "space" is given as a string, successive levels in the stringification will each be indented by this string.

Here is JavaScript example that compares output JSON text strings generated with different "space" options:

<!-- JSON-stringify-space.html
     Copyright (c) FYIcenter.com 
-->
<html>
<body>
<script type="text/javascript">

   document.write("<p>JSON.stringify() Replacer to Transform Values:</p>");
   document.write("<pre>");

   str = '["first", {"name": "Jay", "friends": ["Joe", "Kim"]}]';
   document.write("Input  = "+str+"\n");
   json = JSON.stringify(JSON.parse(str));
   document.write("Output 1 = "+json+"\n");
   json = JSON.stringify(JSON.parse(str), null, 3);
   document.write("Output 2 = "+json+"\n");
   json = JSON.stringify(JSON.parse(str), null, "___");
   document.write("Output 3 = "+json+"\n");

   document.write("</pre>");

</script>
</body>
</html>

Open the above code in a Web browser. You see the following output:

JSON.stringify() Replacer to Transform Values:

Input  = ["first", {"name": "Jay", "friends": ["Joe", "Kim"]}]
Output 1 = ["first",{"name":"Jay","friends":["Joe","Kim"]}]
Output 2 = [
   "first",
   {
      "name": "Jay",
      "friends": [
         "Joe",
         "Kim"
      ]
   }
]
Output 3 = [
___"first",
___{
______"name": "Jay",
______"friends": [
_________"Joe",
_________"Kim"
______]
___}
]

⇒ JSON Validation Online Tools

⇐ JSON-stringify-Filter.html - JSON.stringify() Array Replacer

⇑ Using JSON in JavaScript

⇑⇑ JSON Tutorials