Inventory update (FreeCodeCamp)

update_inventory.js

function updateInventory(curArr, newArr) {
    // All inventory must be accounted for or you're fired!
	
	// using an object so we can assign k'v values
	var curObj = {};
	var returnArr = [];
	var arr = [];
	
	// add to obj so we can access k,v's
	curArr.forEach(function(data){
	    curObj[data[1]] = data[0]
	});
	
	
	for (var i in newArr){
		// if something in the newInv doesn't exist in the curInv, add to it
		if(curObj.hasOwnProperty(newArr[i][1]) === false){
			curObj[newArr[i][1]] = newArr[i][0];
		}
		// since we've added the initial values for the items that don't exist
		// there is no reason to append them
		else {
		// append the values
		curObj[newArr[i][1]] += newArr[i][0];
		}
	}

	
	// push the values from our obj to an arr to return
	for(var x in curObj){
		// console.log(String.charCodeAt(x.toLowerCase()));
		returnArr.push([curObj[x],x]);
	}

	// sort by second col (item text) if larger than next;
	returnArr.sort(function(a,b){
		return a[1] > b[1];	
	});

	return returnArr;
	
}