dump() - Javascript equivalent of PHP's print_r() function

The moment I saw the print_r() function of PHP, I fell in love with it. It is a very necessary function and I cannot understand why no other language supports it. JavaScript is one such language. So, I have ported the print_r function to javascript.

/**
 * Function : dump()
 * Arguments: The data - array,hash(associative array),object
 *    The level - OPTIONAL
 * Returns  : The textual representation of the array.
 * This function was inspired by the print_r function of PHP.
 * This will accept some data as the argument and return a
 * text that will be a more readable version of the
 * array/hash/object that is given.
 * Docs: http://www.openjs.com/scripts/others/dump_function_php_print_r.php
 */
function dump(arr,level) {
	var dumped_text = "";
	if(!level) level = 0;
	
	//The padding given at the beginning of the line.
	var level_padding = "";
	for(var j=0;j<level+1;j++) level_padding += "    ";
	
	if(typeof(arr) == 'object') { //Array/Hashes/Objects 
		for(var item in arr) {
			var value = arr[item];
			
			if(typeof(value) == 'object') { //If it is an array,
				dumped_text += level_padding + "'" + item + "' ...\n";
				dumped_text += dump(value,level+1);
			} else {
				dumped_text += level_padding + "'" + item + "' => \"" + value + "\"\n";
			}
		}
	} else { //Stings/Chars/Numbers etc.
		dumped_text = "===>"+arr+"<===("+typeof(arr)+")";
	}
	return dumped_text;
}

This is how the function is called. In this example we will give a complex array as the argument.

//Calling the function...
function init() {
	var arra = new Array("So long",'s',42,42.13,"Hello World");
	var assoc = {
		"val"  : "New",
		"number" : 8,
		"theting" : arra
	};
	
	alert(dump(assoc));
}
window.onload=init;

The result will be returned in the following format...

'val' => "New"
'number' => "8"
'theting' ...
   '0' => "So long"
   '1' => "s"
   '2' => "42"
   '3' => "42.13"
   '4' => "Hello World"

You can alert the returned text - if it is small. If there is a large amount of content, put the data into a textarea. This will make reading easier.

Original Post

function str_repeat(str, repeat) {

  var output = '';

  for (var i = 0; i < repeat; i++) {

    output += str;

  }

  return output;

}

var MAX_DEPTH = 10;

function print_r(obj, indent, depth) {

  var ws = '    ';

  var output = '';

  indent = (!indent) ? 0 : indent;

  depth = (!depth) ? 0 : depth;

  if (depth > MAX_DEPTH) {

    return str_repeat(ws, indent) + '*Maximum Depth Reached*\n';

  }

  if (typeof(obj) == "object") {

    output += (indent == 0) ? typeof(obj) + '\n(\n' : '';

    indent++;

    var child = '';

    for (var key in obj) {

      try {

        child = obj[key];

      }

      catch (e) {

        child = '*Unable To Evaluate*';

      }

      output += str_repeat(ws, indent) + '['+key+'] => ';

      if (typeof(child) == "object") {

        indent++;

        output += typeof(child) + '\n';

        output += str_repeat(ws, indent) + '(\n';

        output += print_r(child, indent, depth+1);

        output += str_repeat(ws, indent) + ')\n';

        indent--;

      }

      else {

        output += child + '\n';

      }

    }

    indent--;

    output += (indent == 0) ? ')\n' : '';

    return output;

  }

  else {

    return str_repeat(ws, indent) + obj + '\n';

  }

}

dump() - Javascript equivalent of PHP's print_r() function

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