takes in ar array of strings, and returns a grouped object

array2groupedobject.js

module.exports = function(arr,callback){

	var groupByObj = {};
	if(arr.length == 0){
		callback(groupByObj);
	}
	var count = 0;
	

	arr.forEach(function(val){

		count++;

		if(groupByObj.hasOwnProperty(val)){
			groupByObj[val]++;
		}else{
			groupByObj[val] = 1;
		}

		if(arr.length == count){
			callback(groupByObj);
		}
	});


}