code: function(index, valObj, clone) {
              var current = this.jsonQ_current;
              //return if incorrect index is given
              if (isNaN(index) && index != "first" && index != "last") {
                  error(index + 'is not a valid index.');
                  return this;
              }
  
              for (var i = 0, ln = current.length; i < ln; i++) {
                  var pathC = current[i].path.concat([]),
                      lastKey = pathC.pop(),
                      parRef = this.pathValue(pathC),
                      type = objType(parRef[lastKey]),
                      objLn = parRef[lastKey].length;
  
  
                  //to limit index
                  var idx = index < 0 || index == "first" ? 0 : index > objLn || index == "last" ? objLn : index;
  
  
                  //if array push
                  if (type == 'array') {
                      valObj = clone ? jsonQ.clone(valObj) : valObj;
  
                      parRef[lastKey].splice(idx, 0, valObj);
                  }
  
                  //if string concatenate , if number add
                  else if (type == 'string') {
                      var str = parRef[lastKey];
                      parRef[lastKey] = str.substring(0, idx) + valObj + str.substring(idx, objLn);
                  }
  
  
              }
              return this;
  
          }
docs: to append at specific index of values of current