Add code of chapter 06

chapter_06/activity_6.01/main.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+  "errors"
+  "fmt"
+)
+
+var (
+  ErrInvalidLastName      = errors.New("invalid last name")
+  ErrInvalidRoutingNumber = errors.New("invalid routing number")
+)
+
+func main() {
+
+  fmt.Println(ErrInvalidLastName)
+  fmt.Println(ErrInvalidRoutingNumber)
+
+}

chapter_06/activity_6.02/main.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+  "errors"
+  "fmt"
+  "strings"
+)
+
+type directDeposit struct {
+  lastName      string
+  firstName     string
+  bankName      string
+  routingNumber int
+  accountNumber int
+}
+
+var (
+  ErrInvalidLastName      = errors.New("invalid last name")
+  ErrInvalidRoutingNumber = errors.New("invalid routing number")
+)
+
+func (d *directDeposit) validateRoutingNumber() error {
+
+  if d.routingNumber < 100 {
+    return ErrInvalidRoutingNumber
+  }
+  return nil
+
+}
+
+func (d *directDeposit) validateLastName() error {
+
+  d.lastName = strings.TrimSpace(d.lastName)
+  if len(d.lastName) == 0 {
+    return ErrInvalidLastName
+  }
+  return nil
+
+}
+
+func (d *directDeposit) report() {
+
+  fmt.Println(strings.Repeat("*", 40))
+  fmt.Println("Last Name:     ", d.lastName)
+  fmt.Println("First Name:    ", d.firstName)
+  fmt.Println("Bank Name:     ", d.bankName)
+  fmt.Println("Routing Number:", d.routingNumber)
+  fmt.Println("Account Number:", d.accountNumber)
+
+}
+
+func main() {
+
+  dp := directDeposit{
+    "",
+    "Abe",
+    "XYZ Inc",
+    17,
+    1809,
+  }
+
+  if err := dp.validateRoutingNumber(); err != nil {
+    fmt.Println(err)
+  }
+  if err := dp.validateLastName(); err != nil {
+    fmt.Println(err)
+  }
+  dp.report()
+
+}

chapter_06/activity_6.03/main.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+  "errors"
+  "fmt"
+  "strings"
+)
+
+type directDeposit struct {
+  lastName      string
+  firstName     string
+  bankName      string
+  routingNumber int
+  accountNumber int
+}
+
+var (
+  ErrInvalidLastName      = errors.New("invalid last name")
+  ErrInvalidRoutingNumber = errors.New("invalid routing number")
+)
+
+func (d *directDeposit) validateRoutingNumber() error {
+
+  if d.routingNumber < 100 {
+    panic(ErrInvalidRoutingNumber)
+  }
+  return nil
+
+}
+
+func (d *directDeposit) validateLastName() error {
+
+  d.lastName = strings.TrimSpace(d.lastName)
+  if len(d.lastName) == 0 {
+    return ErrInvalidLastName
+  }
+  return nil
+
+}
+
+func (d *directDeposit) report() {
+
+  fmt.Println(strings.Repeat("*", 40))
+  fmt.Println("Last Name:     ", d.lastName)
+  fmt.Println("First Name:    ", d.firstName)
+  fmt.Println("Bank Name:     ", d.bankName)
+  fmt.Println("Routing Number:", d.routingNumber)
+  fmt.Println("Account Number:", d.accountNumber)
+
+}
+
+func main() {
+
+  dp := directDeposit{
+    "",
+    "Abe",
+    "XYZ Inc",
+    17,
+    1809,
+  }
+
+  _ = dp.validateRoutingNumber()
+  if err := dp.validateLastName(); err != nil {
+    fmt.Println(err)
+  }
+  dp.report()
+
+}

chapter_06/activity_6.04/main.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+  "errors"
+  "fmt"
+  "strings"
+)
+
+type directDeposit struct {
+  lastName      string
+  firstName     string
+  bankName      string
+  routingNumber int
+  accountNumber int
+}
+
+var (
+  ErrInvalidLastName      = errors.New("invalid last name")
+  ErrInvalidRoutingNumber = errors.New("invalid routing number")
+)
+
+func (d *directDeposit) validateRoutingNumber() error {
+
+  defer func() {
+    if err := recover(); err == ErrInvalidRoutingNumber {
+      fmt.Println(err)
+    }
+  }()
+
+  if d.routingNumber < 100 {
+    panic(ErrInvalidRoutingNumber)
+  }
+  return nil
+
+}
+
+func (d *directDeposit) validateLastName() error {
+
+  d.lastName = strings.TrimSpace(d.lastName)
+  if len(d.lastName) == 0 {
+    return ErrInvalidLastName
+  }
+  return nil
+
+}
+
+func (d *directDeposit) report() {
+
+  fmt.Println(strings.Repeat("*", 40))
+  fmt.Println("Last Name:     ", d.lastName)
+  fmt.Println("First Name:    ", d.firstName)
+  fmt.Println("Bank Name:     ", d.bankName)
+  fmt.Println("Routing Number:", d.routingNumber)
+  fmt.Println("Account Number:", d.accountNumber)
+
+}
+
+func main() {
+
+  dp := directDeposit{
+    "",
+    "Abe",
+    "XYZ Inc",
+    17,
+    1809,
+  }
+
+  _ = dp.validateRoutingNumber()
+  if err := dp.validateLastName(); err != nil {
+    fmt.Println(err)
+  }
+  dp.report()
+
+}

chapter_06/example_1/main.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+  "errors"
+  "fmt"
+)
+
+func main() {
+  test()
+  fmt.Println("This line will not get printed")
+}
+func test() {
+  n := func() {
+    fmt.Println("Defer in test")
+  }
+  defer n()
+  msg := "good-bye"
+  message(msg)
+}
+func message(msg string) {
+  f := func() {
+    fmt.Println("Defer in message func")
+  }
+  defer f()
+  if msg == "good-bye" {
+    panic(errors.New("something went wrong"))
+  }
+}

chapter_06/example_2/main.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+  "errors"
+  "fmt"
+)
+
+func main() {
+  a()
+  fmt.Println("This line will now get printed from main() function")
+}
+func a() {
+  b("good-bye")
+  fmt.Println("Back in function a()")
+}
+func b(msg string) {
+  defer func() {
+    if r := recover(); r != nil {
+      fmt.Println("error in func b()", r)
+    }
+  }()
+  if msg == "good-bye" {
+    panic(errors.New("something went wrong"))
+  }
+  fmt.Print(msg)
+}

chapter_06/exercise_6.01/main.go

@@ -0,0 +1,17 @@
+package main
+
+import "fmt"
+
+func main() {
+
+  nums := []int{2, 4, 6, 8}
+  total := 0
+
+  //  for i := 0; i <= 10; i++ {
+  for num, _ := range nums {
+    total += num
+  }
+
+  fmt.Println("Total:", total)
+
+}

chapter_06/exercise_6.02/main.go

@@ -0,0 +1,16 @@
+package main
+
+import "fmt"
+
+func main() {
+
+  km := 2
+
+  //  if km > 2 {
+  if km >= 2 {
+    fmt.Println("Take the car")
+  } else {
+    fmt.Println("Going to walk today")
+  }
+
+}

chapter_06/exercise_6.03/main.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+  "errors"
+  "fmt"
+)
+
+var (
+  ErrHourlyRate  = errors.New("invalid hourly rate")
+  ErrHoursWorked = errors.New("invalid hours worked per week")
+)
+
+func main() {
+
+  pay, err := payDay(81, 50)
+  if err != nil {
+    fmt.Println(err)
+  }
+
+  pay, err = payDay(80, 5)
+  if err != nil {
+    fmt.Println(err)
+  }
+
+  pay, err = payDay(80, 50)
+  if err != nil {
+    fmt.Println(err)
+  }
+
+  fmt.Println(pay)
+
+}
+
+func payDay(hoursWorked, hourlyRate int) (int, error) {
+
+  if hourlyRate < 10 || hourlyRate > 75 {
+    return 0, ErrHourlyRate
+  }
+  if hoursWorked < 0 || hoursWorked > 80 {
+    return 0, ErrHoursWorked
+  }
+
+  if hoursWorked > 40 {
+    hoursOver := hoursWorked - 40
+    overTime := hoursOver * 2
+    regularPay := 40 * hourlyRate
+    return regularPay + overTime, nil
+  }
+
+  return hoursWorked * hourlyRate, nil
+
+}

chapter_06/exercise_6.04/main.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+  "errors"
+  "fmt"
+)
+
+var (
+  ErrHourlyRate  = errors.New("invalid hourly rate")
+  ErrHoursWorked = errors.New("invalid hours worked per week")
+)
+
+func main() {
+
+  pay := payDay(81, 50)
+  fmt.Println(pay)
+
+}
+
+func payDay(hoursWorked, hourlyRate int) int {
+
+  report := func() {
+    fmt.Printf("hoursWorked: %d\nhourlyRate: %d\n", hoursWorked, hourlyRate)
+  }
+  defer report()
+
+  if hourlyRate < 10 || hourlyRate > 75 {
+    panic(ErrHourlyRate)
+  }
+  if hoursWorked < 0 || hoursWorked > 80 {
+    panic(ErrHoursWorked)
+  }
+
+  if hoursWorked > 40 {
+    hoursOver := hoursWorked - 40
+    overTime := hoursOver * 2
+    regularPay := 40 * hourlyRate
+    return regularPay + overTime
+  }
+
+  return hoursWorked * hourlyRate
+
+}

chapter_06/exercise_6.05/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+  "errors"
+  "fmt"
+)
+
+var (
+  ErrHourlyRate  = errors.New("invalid hourly rate")
+  ErrHoursWorked = errors.New("invalid hours worked per week")
+)
+
+func main() {
+
+  pay := payDay(100, 25)
+  fmt.Println(pay)
+  pay = payDay(100, 200)
+  fmt.Println(pay)
+  pay = payDay(60, 25)
+  fmt.Println(pay)
+
+}
+
+func payDay(hoursWorked, hourlyRate int) int {
+
+  defer func() {
+    if r := recover(); r != nil {
+      if r == ErrHourlyRate {
+        fmt.Printf("hourly rate: %d -> err: %v\n\n", hourlyRate, r)
+      }
+      if r == ErrHoursWorked {
+        fmt.Printf("hours worked: %d -> err: %v\n\n", hoursWorked, r)
+      }
+    }
+    fmt.Printf("Pay was calculated based on:\nhours worked: %d\nhourly rate: %d\n",
+      hoursWorked, hourlyRate)
+  }()
+
+  if hourlyRate < 10 || hourlyRate > 75 {
+    panic(ErrHourlyRate)
+  }
+  if hoursWorked < 0 || hoursWorked > 80 {
+    panic(ErrHoursWorked)
+  }
+
+  if hoursWorked > 40 {
+    hoursOver := hoursWorked - 40
+    overTime := hoursOver * 2
+    regularPay := 40 * hourlyRate
+    return regularPay + overTime
+  }
+
+  return hoursWorked * hourlyRate
+
+}