Javascript object to formatted string

Question

How to output an object as a readable string with formatting (structured like with <pre>) ?

No jQuery possible.

My object looks like this using console.log.

Object
 title: "Another sting"
 type: "tree"
 options: Object
 paging: "20"
 structuretype: "1"
 columns: Object
 ...
 description: "This is a string"
 ...

What is the best to convert it to a structured string?

My attempt:

I tried using stringify() to get the JSON structure. I could then write my own parser, but maybe there are already any implementations?

• CharliePrynn: Do you mind using a framework? api.jquery.com/jQuery.parseJSON
• Hidde: @CharliePrynn He said, no jQuery possible.

Answer 1

JSON.stringify includes a formatting argument:

JSON.stringify(value[, replacer [, space]])

The space argument may be used to control spacing in the final string. If it is a number, successive levels in the stringification will each be indented by this many space characters (up to 10). If it is a string, successive levels will indented by this string (or the first ten characters of it).

Using a tab character mimics standard pretty-print appearance

https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/JSON/stringify

Is that enough formatting for what you need? E.g. try:

 JSON.stringify( object, null, 2 );

Otherwise, http://code.google.com/p/google-code-prettify/ is a standalone JSON to HTML pretty printer. Used by stackoverflow and google code, I believe.

• Shlomo: Thank you for the solution, I did not know about the space parameter. Indeed I can use this combined with removing unwanted characters {, } and ".

Answer 2

In the meantime I came up with this function, maybe someone can use it:

addIndent: function(nSpaces) {
 var strOutput = '';
 for(var i = 0; i < nSpaces; i++) {
 strOutput += '--';
 }
 return strOutput; 
 }
parseObjToStr: function(oObject, nLevel) {
 var that = this;
 var strOutput = '';
 nLevel = nLevel || 0;
 for(var oEl in oObject) {
 if(typeof oObject[oEl] === 'object' || Object.prototype.toString.call( oObject[oEl] ) === '[object Array]') 
 {
 strOutput += that.addIndent(nLevel) + oEl + "<br />";
 strOutput += that.parseObjToStr( oObject[oEl], nLevel+1);
 } 
 else 
 {
 strOutput += that.addIndent(nLevel) + oEl + " = " + oObject[oEl] + "<br />";
 }
 }
 return strOutput;
 }