function print_r (array, return_val) {
  // http://kevin.vanzonneveld.net
  // +   original by: Michael White (http://getsprink.com)
  // +   improved by: Ben Bryan
  // +      input by: Brett Zamir (http://brett-zamir.me)
  // +      improved by: Brett Zamir (http://brett-zamir.me)
  // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // -    depends on: echo
  // *     example 1: print_r(1, true);
  // *     returns 1: 1
  var output = '',
    pad_char = ' ',
    pad_val = 4,
    d = this.window.document,
    getFuncName = function (fn) {
      var name = (/\W*function\s+([\w\$]+)\s*\(/).exec(fn);
      if (!name) {
        return '(Anonymous)';
      }
      return name[1];
    },
    repeat_char = function (len, pad_char) {
      var str = '';
      for (var i = 0; i < len; i++) {
        str += pad_char;
      }
      return str;
    },
    formatArray = function (obj, cur_depth, pad_val, pad_char) {
      if (cur_depth > 0) {
        cur_depth++;
      }

      var base_pad = repeat_char(pad_val * cur_depth, pad_char);
      var thick_pad = repeat_char(pad_val * (cur_depth + 1), pad_char);
      var str = '';

      if (typeof obj === 'object' && obj !== null && obj.constructor && getFuncName(obj.constructor) !== 'PHPJS_Resource') {
        str += 'Array\n' + base_pad + '(\n';
        for (var key in obj) {
          if (Object.prototype.toString.call(obj[key]) === '[object Array]') {
            str += thick_pad + '[' + key + '] => ' + formatArray(obj[key], cur_depth + 1, pad_val, pad_char);
          }
          else {
            str += thick_pad + '[' + key + '] => ' + obj[key] + '\n';
          }
        }
        str += base_pad + ')\n';
      }
      else if (obj === null || obj === undefined) {
        str = '';
      }
      else { // for our "resource" class
        str = obj.toString();
      }

      return str;
    };

  output = formatArray(array, 0, pad_val, pad_char);

  if (return_val !== true) {
    if (d.body) {
      this.echo(output);
    }
    else {
      try {
        d = XULDocument; // We're in XUL, so appending as plain text won't work; trigger an error out of XUL
        this.echo('<pre xmlns="http://www.w3.org/1999/xhtml" style="white-space:pre;">' + output + '</pre>');
      } catch (e) {
        this.echo(output); // Outputting as plain text may work in some plain XML
      }
    }
    return true;
  }
  return output;
}

print_r(1, true);

1