function getInput() {

                            // get the values from the user
                            let loanBalance = document.getElementById('balance').value;
                            let loanTerm = document.getElementById('term').value;
                            let loanRate = document.getElementById('rate').value;
                        
                        
                            // parse into integers
                            loanBalance = parseInt(loanBalance);
                            // loanTerm = parseInt(loanTerm);
                            // loanRate = parseInt(loanRate);
                        
                            // call calculateValues
                            numbers = calculateValues(loanBalance, loanTerm, loanRate);
                            // call displayValues
                            //   displayValues(loanBalance, numbers, loanTerm);
                        
                            // check if values are integers
                            // if (Number.isInteger(loanBalance) && Number.isInteger(loanTerm) && Number.isInteger(loanRate)) {
                        
                            // } else {
                            //     alert('Enter A Integer');
                            // }
                        
                        }
                        
                        function calculateValues(loanBalance, loanTerm, loanRate) {
                        
                            let numbers = [];
                        
                            //  let previousRemainingBalance = loanBalance;
                        
                            let totalMonthlyPayment = CalcMonthlyPayment(loanBalance, loanRate, loanTerm);
                        
                            let balance = loanBalance;
                            let totalInterest = 0.0;
                            let monthlyInterest = 0.0;
                            let monthlyPrincipal = 0.0;
                            let monthlyRate = CalcMonthlyRate(loanRate);
                            let newMonthlyRate = 0.0;
                        
                            let totalCombined = totalMonthlyPayment * loanTerm
                        
                            for (let i = 1; i <= loanTerm; i++) {
                                monthlyInterest = CalcMonthlyInterest(loanBalance, monthlyRate);
                                newMonthlyRate = CalcNewMonthlyInterest(balance, monthlyRate);
                                totalInterest += newMonthlyRate;
                                monthlyPrincipal = totalMonthlyPayment - newMonthlyRate;
                                balance -= monthlyPrincipal;
                                let balanceformated = Math.abs(balance);
                                let balanceformatedwithcorrection = new Intl.NumberFormat("en-US", {
                                    style: 'currency',
                                    currency: 'USD',
                                    currencyDisplay: 'narrowSymbol',
                                }).format(balanceformated);
                                let totalMonthlyPaymentFormatted = new Intl.NumberFormat("en-US", {
                                    style: 'currency',
                                    currency: 'USD',
                                    currencyDisplay: 'narrowSymbol'
                                }).format(totalMonthlyPayment);
                                let monthlyPrincipalFormatted = new Intl.NumberFormat("en-US", {
                                    style: 'currency',
                                    currency: 'USD',
                                    currencyDisplay: 'narrowSymbol'
                                }).format(monthlyPrincipal);
                                let newMonthlyRateFormatted = new Intl.NumberFormat("en-US", {
                                    style: 'currency',
                                    currency: 'USD',
                                    currencyDisplay: 'narrowSymbol'
                                }).format(newMonthlyRate);
                                let totalInterestFormatted = new Intl.NumberFormat("en-US", {
                                    style: 'currency',
                                    currency: 'USD',
                                    currencyDisplay: 'narrowSymbol'
                                }).format(totalInterest);
                                // Loop until the end of the loan term DOES NOT CHANGE
                        
                                numbers.push(i); // First On The List 
                                // Loop until the end of the loan term the totalMonthlyPayment DOES NOT CHANGE
                                numbers.push((totalMonthlyPaymentFormatted)); // second on the list 
                        
                        
                                numbers.push((monthlyPrincipalFormatted)); // third on the list
                        
                                numbers.push((newMonthlyRateFormatted)) // fouth on the list
                                numbers.push((totalInterestFormatted)) // fifth on the list
                                numbers.push((balanceformatedwithcorrection)) // sixth on the list
                        
                            }
                        
                        
                            // get the table body
                            let tableBody = document.getElementById("results");
                        
                            // get the template row
                            let templateRow = document.getElementById("numbersTemplate");
                        
                        
                            // clear table first
                            tableBody.innerHTML = "";
                        
                            for (let i = 0; i < numbers.length; i += 6) {
                                let tableRow = document.importNode(templateRow.content, true);
                        
                        
                                let rowCols = tableRow.querySelectorAll("td");
                                rowCols[0].textContent = numbers[i];
                                rowCols[1].textContent = numbers[i + 1];
                                rowCols[2].textContent = numbers[i + 2];
                                rowCols[3].textContent = numbers[i + 3];
                                rowCols[4].textContent = numbers[i + 4];
                                rowCols[5].textContent = numbers[i + 5];
                        
                                tableBody.appendChild(tableRow);
                        
                                let balanceformated = new Intl.NumberFormat("en-US", {
                                    style: 'currency',
                                    currency: 'USD',
                                    currencyDisplay: 'narrowSymbol'
                                }).format(loanBalance);
                                let totalCombinedFormatted = new Intl.NumberFormat("en-US", {
                                    style: 'currency',
                                    currency: 'USD',
                                    currencyDisplay: 'narrowSymbol'
                                }).format(totalCombined);
                        
                                document.getElementById("MonthlyPayments").innerHTML = numbers[i + 1]; // displays the monthly payment
                                document.getElementById("TotalPrincipal").innerHTML = balanceformated; // displays the total principal
                                document.getElementById("TotalInterest").innerHTML = numbers[i + 4]; // displays the total interest
                                document.getElementById("TotalCost").innerHTML = totalCombinedFormatted; // displays the total cost
                                document.getElementById("TotalPayments").innerHTML = loanTerm; // displays the total payments
                            }
                        
                            return numbers;
                        }
                        
                        function CalcMonthlyPayment(loanBalance, loanRate, loanTerm) {
                        
                            //  monthlyRate = CalcMonthlyRate(loanRate);
                            let totalMonthlyPayment = (loanBalance) * (loanRate / 1200) / (1 - (1 + loanRate / 1200) ** ((-loanTerm)));
                        
                            return totalMonthlyPayment;
                        }
                        
                        function CalcMonthlyRate(loanRate) {
                            return loanRate / 1200;
                        }
                        
                        function CalcMonthlyInterest(loanBalance, monthlyRate) {
                            // calculate the current remaining balance for the BEFORE calculations of months 
                            // let previousRemainingBalance = loanBalance;
                            let interestPayment = monthlyRate * loanBalance;
                            return interestPayment;
                        }
                        
                        function CalcNewMonthlyInterest(balance, monthlyRate) {
                            // calculate the current remaining balance for the BEFORE calculations of months 
                            // let previousRemainingBalance = loanBalance;
                            let interestPayment = monthlyRate * balance;
                            return interestPayment;
                        }
                        
                    
                    

Code Explaination For Loan Shark

Read more about how I made this application here!