go go go

bank/balance.txt

@@ -0,0 +1 @@
+1900

bank/bank.go

@@ -1,21 +1,27 @@
 package main
 
+import "errors"
 import "fmt"
 import "os"
 import "strconv"
 
 const accountBalanceFile = "balance.txt"
 
-func getBalanceFromFile() float64 {
+func getBalanceFromFile() (float64, error) {
 	data, err := os.ReadFile(accountBalanceFile, )
 
 	if err != nil {
-
+		return 1000, errors.New("Failed to find balance file.")
 	}
 	
 	balanceText := string(data)
-	balance, _ :=strconv.ParseFloat(balanceText, 64)
-	return balance
+	balance, err :=strconv.ParseFloat(balanceText, 64)
+
+	if err != nil {
+		return 1000, errors.New("Failed to parse stored balance value.")
+	}
+
+	return balance, nil
 }
 
 func writeBalanceToFile(balance float64) {
@@ -24,7 +30,13 @@ func writeBalanceToFile(balance float64) {
 }
 
 func main() {
-	var accountBalance = getBalanceFromFile()
+	var accountBalance, err = getBalanceFromFile()
+
+	if err != nil {
+		fmt.Println("ERROR")
+		fmt.Println(err)
+		fmt.Println("-------")
+	}
 
 	fmt.Println("Welcome to Go Bank!")
 

profitCalculator/app.go

@@ -1,11 +1,30 @@
 package main
 
 import "fmt"
+import "errors"
+import "os"
 
 func main() {
-	revenue := getUserInput("Revenue: ")
-	expenses := getUserInput("Expenses: ")
-	taxRate := getUserInput("Tax Rate: ")
+	revenue, err := getUserInput("Revenue: ")
+
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	expenses, err := getUserInput("Expenses: ")
+
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	taxRate, err := getUserInput("Tax Rate: ")
+
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
 
 	ebt, profit, ratio := calculateFinancials(revenue, expenses, taxRate)
 	
@@ -13,6 +32,13 @@ func main() {
 	fmt.Printf("%.1f\n", ebt)
 	fmt.Printf("%.1f\n", profit)
 	fmt.Printf("%.3f", ratio)
+
+	storeResults(ebt, profit, ratio)
+}
+
+func storeResults(ebt, profit, ratio float64) {
+	results := fmt.Sprintf("EBT: %1f\nProfit: %.1f\nRatio: %.3f\n", ebt, profit, ratio)
+	os.WriteFile("results.txt", []byte(results), 0644)
 }
 
 func calculateFinancials(revenue, expenses, taxRate float64) (float64, float64, float64) {
@@ -22,9 +48,14 @@ func calculateFinancials(revenue, expenses, taxRate float64) (float64, float64,
 	return ebt, profit, ratio
 }
 
-func getUserInput(infoText string) float64 {
+func getUserInput(infoText string) (float64, error) {
 	var userInput float64
 	fmt.Print(infoText)
 	fmt.Scan(&userInput)
-	return userInput
+
+	if userInput <= 0 {
+		return 0, errors.New("Value must be a positive number")
+	}
+
+	return userInput, nil
 }

profitCalculator/results.txt

@@ -0,0 +1,3 @@
+EBT: 50.000000
+Profit: 48.5
+Ratio: 1.031