add: switch statement exercises

12-switch/exercises/01/main.go

@@ -0,0 +1,72 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+// ---------------------------------------------------------
+// STORY
+//  You're curious about the richter scales. When reporters
+//  say: "There's been a 5.5 magnitude earthquake",
+//
+//  You want to know what that means.
+//
+//  So, you've decided to write a program to do that for you.
+//
+// EXERCISE
+//  1. Get the earthquake magnitude from the command-line.
+//  2. Display its corresponding description.
+//
+// ---------------------------------------------------------
+// MAGNITUDE                    DESCRIPTION
+// ---------------------------------------------------------
+// Less than 2.0                micro
+// 2.0 to less than 3.0         very minor
+// 3.0 to less than 4.0         minor
+// 4.0 to less than 5.0         light
+// 5.0 to less than 6.0         moderate
+// 6.0 to less than 7.0         strong
+// 7.0 to less than 8.0         major
+// 8.0 to less than 10.0        great
+// 10.0 or more                 massive
+//
+// EXPECTED OUTPUT
+//  go run main.go
+//    Give me the magnitude of the earthquake.
+//
+//  go run main.go ABC
+//    I couldn't get that, sorry.
+//
+//  go run main.go 0.5
+//    0.50 is micro
+//
+//  go run main.go 2.5
+//    2.50 is very minor
+//
+//  go run main.go 3
+//    3.00 is minor
+//
+//  go run main.go 4.5
+//    4.50 is light
+//
+//  go run main.go 5
+//    5.00 is moderate
+//
+//  go run main.go 6
+//    6.00 is strong
+//
+//  go run main.go 7
+//    7.00 is major
+//
+//  go run main.go 8
+//    8.00 is great
+//
+//  go run main.go 11
+//    11.00 is massive
+// ---------------------------------------------------------
+
+func main() {
+}

12-switch/exercises/01/solution/main.go

@@ -0,0 +1,53 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+)
+
+func main() {
+	args := os.Args
+	if len(args) != 2 {
+		fmt.Println("Give me the magnitude of the earthquake.")
+		return
+	}
+
+	richter, err := strconv.ParseFloat(args[1], 64)
+	if err != nil {
+		fmt.Println("I couldn't get that, sorry.")
+		return
+	}
+
+	var desc string
+
+	switch r := richter; {
+	case r < 2:
+		desc = "micro"
+	case r >= 2 && r < 3:
+		desc = "very minor"
+	case r >= 3 && r < 4:
+		desc = "minor"
+	case r >= 4 && r < 5:
+		desc = "light"
+	case r >= 5 && r < 6:
+		desc = "moderate"
+	case r >= 6 && r < 7:
+		desc = "strong"
+	case r >= 7 && r < 8:
+		desc = "major"
+	case r >= 8 && r < 10:
+		desc = "great"
+	default:
+		desc = "meteoric"
+	}
+
+	fmt.Printf("%.2f is %s\n", richter, desc)
+}

12-switch/exercises/02/main.go

@@ -0,0 +1,68 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+// ---------------------------------------------------------
+// EXERCISE
+//  Repeat the previous exercise.
+//
+//  But, this time, get the description and print the
+//  corresponding richter scale.
+//
+//  See the expected outputs.
+//
+// ---------------------------------------------------------
+// MAGNITUDE                    DESCRIPTION
+// ---------------------------------------------------------
+// Less than 2.0                micro
+// 2.0 to less than 3.0         very minor
+// 3.0 to less than 4.0         minor
+// 4.0 to less than 5.0         light
+// 5.0 to less than 6.0         moderate
+// 6.0 to less than 7.0         strong
+// 7.0 to less than 8.0         major
+// 8.0 to less than 10.0        great
+// 10.0 or more                 massive
+//
+// EXPECTED OUTPUT
+//  go run main.go
+//   Tell me the magnitude of the earthquake in human terms.
+//
+//  go run main.go aliens
+//   alien's richter scale is unknown
+//
+//  go run main.go micro
+//   micro's richter scale is less than 2.0
+//
+//  go run main.go "very minor"
+//   very minor's richter scale is 2 - 2.9
+//
+//  go run main.go minor
+//   minor's richter scale is 3 - 3.9
+//
+//  go run main.go light
+//   light's richter scale is 4 - 4.9
+//
+//  go run main.go moderate
+//   moderate's richter scale is 5 - 5.9
+//
+//  go run main.go strong
+//   strong's richter scale is 6 - 6.9
+//
+//  go run main.go major
+//   major's richter scale is 7 - 7.9
+//
+//  go run main.go great
+//   great's richter scale is 8 - 8.9
+//
+//  go run main.go massive
+//   massive's richter scale is 10+
+// ---------------------------------------------------------
+
+func main() {
+}

12-switch/exercises/02/solution/main.go

@@ -0,0 +1,53 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func main() {
+	args := os.Args
+	if len(args) != 2 {
+		fmt.Println("Tell me the magnitude of the earthquake in human terms.")
+		return
+	}
+
+	var richter string
+
+	desc := args[1]
+
+	switch desc {
+	case "micro":
+		richter = "less than 2.0"
+	case "very minor":
+		richter = "2 - 2.9"
+	case "minor":
+		richter = "3 - 3.9"
+	case "light":
+		richter = "4 - 4.9"
+	case "moderate":
+		richter = "5 - 5.9"
+	case "strong":
+		richter = "6 - 6.9"
+	case "major":
+		richter = "7 - 7.9"
+	case "great":
+		richter = "8 - 8.9"
+	case "massive":
+		richter = "10+"
+	default:
+		richter = "unknown"
+	}
+
+	fmt.Printf(
+		"%s's richter scale is %s\n",
+		desc, richter,
+	)
+}

12-switch/exercises/03/main.go

@@ -13,34 +13,8 @@ import (
 )
 
 // ---------------------------------------------------------
-// CHALLENGE
-//  Convert the if statement into a switch statement.
-//
-// EXAMPLE USERS
-//  username: jack
-//  password: 1888
-//
-//  username: inanc
-//  password: 1879
-//
-// EXPECTED OUTPUT
-//  go run main.go
-//    Usage: [username] [password]
-//
-//  go run main.go hacker 42
-//    Access denied for "hacker".
-//
-//  go run main.go jack 1888
-//    Access granted to "jack".
-//
-//  go run main.go inanc 1879
-//    Access granted to "inanc".
-//
-//  go run main.go jack 1879
-//    Invalid password for "jack".
-//
-//  go run main.go inanc 1888
-//    Invalid password for "inanc".
+// EXERCISE
+//  Convert the if statement to a switch statement.
 // ---------------------------------------------------------
 
 const (
@@ -62,7 +36,9 @@ func main() {
 
 	u, p := args[1], args[2]
 
-	// refactor this into switch
+	//
+	// REFACTOR THIS TO A SWITCH
+	//
 	if u != user && u != user2 {
 		fmt.Printf(errUser, u)
 	} else if u == user && p == pass {

12-switch/exercises/03/solution/main.go

@@ -31,10 +31,12 @@ func main() {
 
 	u, p := args[1], args[2]
 
+	// More readable, right? 👍
 	switch {
 	case u != user && u != user2:
 		fmt.Printf(errUser, u)
 	case u == user && p == pass:
+		// notice this one (no more duplication)
 		fallthrough
 	case u == user2 && p == pass2:
 		fmt.Printf(accessOK, u)

12-switch/exercises/04/main.go

@@ -0,0 +1,45 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+// ---------------------------------------------------------
+// STORY
+//  You want to write a program that will manipulate the
+//  given strings to uppercase, lowercase, and title case.
+//
+// EXERCISE
+//  1. Get the operation as the first argument.
+//  2. Get the string to be manipulated as the 2nd argument.
+//
+// HINT
+//  You can find the manipulation functions in the strings
+//  package Go documentation (ToLower, ToUpper, Title).
+//
+// EXPECTED OUTPUT
+//
+//  go run main.go
+//    [command] [string]
+//
+//    Available commands: lower, upper and title
+//
+//  go run main.go lower 'OMG!'
+//    omg!
+//
+//  go run main.go upper 'omg!'
+//    OMG!
+//
+//  go run main.go title "mr. charles darwin"
+//    Mr. Charles Darwin
+//
+//  go run main.go genius "mr. charles darwin"
+//    Unknown command: "genius"
+// ---------------------------------------------------------
+
+func main() {
+
+}

12-switch/exercises/04/solution/main.go

@@ -0,0 +1,38 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+const usage = `[command] [string]
+
+Available commands: lower, upper and title`
+
+func main() {
+	args := os.Args
+	if len(args) != 3 {
+		fmt.Println(usage)
+		return
+	}
+
+	cmd, str := args[1], args[2]
+	switch cmd {
+	case "lower":
+		fmt.Println(strings.ToLower(str))
+	case "upper":
+		fmt.Println(strings.ToUpper(str))
+	case "title":
+		fmt.Println(strings.Title(str))
+	default:
+		fmt.Printf("Unknown command: %q\n", cmd)
+	}
+}

12-switch/exercises/05/main.go

@@ -0,0 +1,61 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"time"
+)
+
+// ---------------------------------------------------------
+// EXERCISE
+//  Refactor the previous exercise from the if statement
+//  section.
+//
+//  "Print the number of days in a given month."
+//
+//  Use a switch statement instead of if statements.
+// ---------------------------------------------------------
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Println("Give me a month name")
+		return
+	}
+
+	year := time.Now().Year()
+	leap := year%4 == 0 && (year%100 != 0 || year%400 == 0)
+
+	days, month := 28, os.Args[1]
+
+	if m := strings.ToLower(month); m == "april" ||
+		m == "june" ||
+		m == "september" ||
+		m == "november" {
+		days = 30
+	} else if m == "january" ||
+		m == "march" ||
+		m == "may" ||
+		m == "july" ||
+		m == "august" ||
+		m == "october" ||
+		m == "december" {
+		days = 31
+	} else if m == "february" {
+		if leap {
+			days = 29
+		}
+	} else {
+		fmt.Printf("%q is not a month.\n", month)
+		return
+	}
+
+	fmt.Printf("%q has %d days.\n", month, days)
+}

12-switch/exercises/05/solution/main.go

@@ -0,0 +1,44 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"time"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Println("Give me a month name")
+		return
+	}
+
+	year := time.Now().Year()
+	leap := year%4 == 0 && (year%100 != 0 || year%400 == 0)
+
+	days, month := 28, os.Args[1]
+
+	switch strings.ToLower(month) {
+	case "april", "june", "september", "november":
+		days = 30
+	case "january", "march", "may", "july",
+		"august", "october", "december":
+		days = 31
+	case "february":
+		if leap {
+			days = 29
+		}
+	default:
+		fmt.Printf("%q is not a month.\n", month)
+		return
+	}
+
+	fmt.Printf("%q has %d days.\n", month, days)
+}

12-switch/questions/questions.md

@@ -1,3 +1,4 @@
 ## ?
-* text *CORRECT*
-* text
+1. text *CORRECT*
+2. text
+E