String data manipulated given CSV variables

Question

The Requirements:

List the expensable items sorted by date and location given two variables: 'categories' and 'expenses'. The Categories variable provides the following information in order: Category ID, Category Name, and whether the category is expensable (Y/N). The Expenses variable provides the following information in order: Location, Date, Item Description, Cost, and Category Code. Each line should be displayed in the format "DATE: LOCATION - $TOTAL".

I put it together in a single JavaScript executable.

The code:

// Input Values
var categories = "CFE,Coffee,Y\nFD,Food,Y\nPRS,Personal,N";
var expenses = "Starbucks,3/10/2018,Iced Americano,4.28,CFE\nStarbucks,3/10/2018,Nitro Cold Brew,3.17,CFE\nStarbucks,3/10/2018,Souvineer Mug,8.19,PRS\nStarbucks,3/11/2018,Nitro Cold Brew,3.17,CFE\nHigh Point Market,3/11/2018,Iced Americano,2.75,CFE\nHigh Point Market,3/11/2018,Pastry,2.00,FD\nHigh Point Market,3/11/2018,Gift Card,10.00,PRS";
var AcceptableExpenses = GetAcceptableExpenses(GetAcceptableCategories(categories), expenses)
AcceptableExpenses.forEach (AcceptableExpense =>{
 console.log(AcceptableExpense.join(''))
})
function GetAcceptableExpenses(AcceptableCategories, expenses){
 var ExpensesList = expenses.split("\n")
 var AcceptableExpenseTotals = []
 var categoryIndex = 4
 var venderIndex = 0
 var dateIndex = 1
 var priceIndex = 3
 var venderDate = []
 ExpensesList.forEach(expense => {
 var expenseItemized = expense.split(',')
 if ((categoryIndex < expenseItemized.length) && IsExpenseItemAcceptable(AcceptableCategories, expenseItemized[categoryIndex])){
 venderDate = [expenseItemized[dateIndex], ": ", expenseItemized[venderIndex], " - $"].join('')
 if ( IsVenderDateIncluded(AcceptableExpenseTotals, venderDate) ){
 UpdatePrice(AcceptableExpenseTotals, venderDate, expenseItemized[priceIndex] )
 }
 else{
 AcceptableExpenseTotals.push([venderDate, expenseItemized[priceIndex] ])
 }
 }
 })
 return AcceptableExpenseTotals
}
function IsVenderDateIncluded(AcceptableExpenseTotals, venderDate){
 var venderDateIndex = 0
 var IsIncluded = false
 AcceptableExpenseTotals.forEach( AcceptableExpenseTotal =>{
 if (AcceptableExpenseTotal[venderDateIndex] === venderDate){
 IsIncluded = true
 }
 })
 return IsIncluded
}
function UpdatePrice(AcceptableExpenseTotals, venderDate, price ){
 var venderDateIndex = 0
 var priceIndex = 1
 AcceptableExpenseTotals.forEach( AcceptableExpenseTotal =>{
 if (AcceptableExpenseTotal[venderDateIndex] === venderDate){
 AcceptableExpenseTotal[priceIndex] = parseFloat( price) + parseFloat(AcceptableExpenseTotal[priceIndex])
 return
 }
 })
}
function IsExpenseItemAcceptable(AcceptableCategories, category ){
 var IsAcceptable = false
 AcceptableCategories.forEach(AcceptableCategory => {
 if (AcceptableCategory === category){
 IsAcceptable = true
 }
 })
 return IsAcceptable
}
function GetAcceptableCategories(categories){
 var categoryList = categories.split("\n")
 var AcceptableCategory = []
 for (i = 0; i < categoryList.length; i++){
 var categoryData = categoryList[i].split(',');
 var locationOf_IsExpensible = 2;
 var locationOf_Category = 0;
 if (locationOf_IsExpensible < categoryData.length ){
 if (categoryData[locationOf_IsExpensible]==="Y"){
 AcceptableCategory.push(categoryData[locationOf_Category])
 }
 }
 }
 return AcceptableCategory
}

Answer 1

This code is a decent start, as it uses ES6 features like arrow functions. However it could take advantage of many Javascript features - e.g. IsExpenseItemAcceptable could be reduced to a single line using Array.includes(). Additionally, the index variables can be eliminated using the ES6 feature Destructuring assignment - specifically array destructuring.

Instead of lines like

var expenseItemized = expense.split(',')
if ((categoryIndex < expenseItemized.length) && IsExpenseItemAcceptable(AcceptableCategories, expenseItemized[categoryIndex])){

Destructuring assignment can greatly simplify this to something like:

const [vendor, date, item, price, category] = expense.split(','); 
if (category && IsExpenseItemAcceptable(AcceptableCategories, category)){

Not only is that condition shorter, it doesn't require the use of the index and is more readable (and a typo on the word "vendor" was fixed).

In the example above const was used instead of var. It is recommended that const be the default keyword for initializing variables. If assignment is required, then use let.

The function GetAcceptableCategories could be simplified using Array.reduce(), similar to Array.forEach().

The data structure could be changed from an array to a plain object - i.e. {} to provide a mapping of vendor and date combinations to prices. This would allow the elimination of the functions updatePrice and IsVenderDateIncluded because the loop could be simplified to:

if (category && IsExpenseItemAcceptable(AcceptableCategories, category)){
 const vendorDate = [date, ": ", vendor, " - $"].join('')
 if (vendorDate in AcceptableExpenseTotals) {
 AcceptableExpenseTotals[vendorDate] += parseFloat(price);
 }
 else{
 AcceptableExpenseTotals[vendorDate] = parseFloat(price);
 }
}

This would require reformatting the output - e.g.

for (const [vendorDate, price] of Object.entries(AcceptableExpenses)) {
 console.log(vendorDate, price);
}

• amalgamate: Thanks for your help. I know the checkmark and point should be enough thanks but I wanted to preface this note with thanks before I bring up the smallest of notes: I looked up vender and vendor because while I am a terrible speller it was not actually my spelling... So it turns out there are 2 words, vender and vendor. From what I gather vender is retail and vendor is manufacture supply so in this case vender was probably the correct choice.

Answer 2

1) I would like to add that the solution is not using object-oriented. Which would add alot to the readability and extensibility of the code. I think practically its a better as a solution then "free style - incremental programming".

The main object can be for example: - ExpensesSheet or ExpensesCalculator - You can pass proper formatted input object into it - You can set up filters - You can execute the query

2) You should consider translating long statements into functions that can be read as English

3) ExceptableCategories can be a map instead of an array to lookup isCategoryAcceptable in O(1)

4) var is old and considered bad way to define variables - js linters will recommend using const or let

i.e.: Here's a translation of your code to object-oriented style.

Note: To hide the private functions from the class interface I buried them as functions inside functions, that is not a style recommendation, just a solution I picked on the way.

class ExpensesCalculator {
 constructor(categories, expenses) {
 this.expensibleCateogries = new Map();
 this.expensibleExpenses = {};
 initExpensibleCategories(this, categories);
 initExpensibleExpenses(this, expenses);
 calculateTotal(this);
 function initExpensibleCategories(_this, categories) {
 categories.split('\n').forEach(category => {
 const [categoryID, categoryName, isExpensable] = category.split(',');
 if(isExpensable) {
 _this.expensibleCateogries.set(categoryID, categoryName);
 }
 })
 }
 function initExpensibleExpenses(_this, expenses) {
 expenses.split('\n').forEach(expense => {
 const [vendor, date, item, price, category] = expense.split(',');
 if (_this.expensibleCateogries.has(category)) {
 if(!_this.expensibleExpenses[date]) {
 _this.expensibleExpenses[date] = {};
 }
 if(!_this.expensibleExpenses[date][vendor]) {
 _this.expensibleExpenses[date][vendor] = 0;
 }
 _this.expensibleExpenses[date][vendor] += parseFloat(price);
 }
 })
 }
 function calculateTotal(_this) {
 _this.result = [];
 Object.keys(_this.expensibleExpenses).forEach(ddate => {
 Object.keys(_this.expensibleExpenses[ddate]).forEach(vendor=>{
 _this.result.push({
 date: new Date(ddate), 
 vendor, 
 total: _this.expensibleExpenses[ddate][vendor]})
 })
 })
 }
 }
 printReport() {
 this.result
 .sort(byDateAndVedor)
 .forEach(item=>{
 console.log(`${getFormattedDate(item.date)}: ${item.vendor} - ${item.total}`);
 })
 function byDateAndVedor(a,b) {
 return a.date - b.date === 0 ? // if date is same
 ('' + a.vendor).localeCompare(b.vendor) : // then sort by vendor
 a.date - b.date // otherwise soft by date
 }
 function getFormattedDate(date) {
 const dateTimeFormat = 
 new Intl.DateTimeFormat('en', { year: 'numeric', month: '2-digit', day: '2-digit' });
 const [{ value: month },,{ value: day },,{ value: year }] = dateTimeFormat.formatToParts(date);
 return `${month}/${day}/${year}`;
 }
 }
}
// Input Values
const categories = "CFE,Coffee,Y\nFD,Food,Y\nPRS,Personal,N";
const expenses = "Starbucks,3/10/2018,Iced Americano,4.28,CFE\nStarbucks,3/10/2018,Nitro Cold Brew,3.17,CFE\nStarbucks,3/10/2018,Souvineer Mug,8.19,PRS\nStarbucks,3/11/2018,Nitro Cold Brew,3.17,CFE\nHigh Point Market,3/11/2018,Iced Americano,2.75,CFE\nHigh Point Market,3/11/2018,Pastry,2.00,FD\nHigh Point Market,3/11/2018,Gift Card,10.00,PRS";
const expensesCalculator = new ExpensesCalculator(categories, expenses);
expensesCalculator.printReport();