restructure: arrays and slices

2019-01-29 19:43:12 +03:00
parent 096ac9c251
commit c43d152d33
108 changed files with 92 additions and 243 deletions
--- a/16-slices/exercises/01-declare-nil/main.go
+++ b/16-slices/exercises/01-declare-nil/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
+
+// ---------------------------------------------------------
+// EXERCISE: Declare nil slices
+//
+//  1. Declare the following slices as nil slices:
+//
+//    1. The names of your friends (names slice)
+//
+//    2. The distances to locations (distances slice)
+//
+//    3. A data buffer (data slice)
+//
+//    4. Currency exchange ratios (ratios slice)
+//
+//    5. Up/Down status of web servers (alives slice)
+//
+//
+//  2. Print their type, length and whether they're equal to nil value or not.
+//
+//
+// EXPECTED OUTPUT
+//  names    : []string 0 true
+//  distances: []int 0 true
+//  data     : []uint8 0 true
+//  ratios   : []float64 0 true
+//  alives   : []bool 0 true
+// ---------------------------------------------------------
+
+func main() {
+}
--- a/16-slices/exercises/01-declare-nil/solution/main.go
+++ b/16-slices/exercises/01-declare-nil/solution/main.go
@ -0,0 +1,26 @@
+// 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"
+
+func main() {
+	var (
+		names     []string  // The names of your friends
+		distances []int     // The distances
+		data      []byte    // A data buffer
+		ratios    []float64 // Currency exchange ratios
+		alives    []bool    // Up/Down status of web servers
+	)
+
+	fmt.Printf("names    : %T %d %t\n", names, len(names), names == nil)
+	fmt.Printf("distances: %T %d %t\n", distances, len(distances), distances == nil)
+	fmt.Printf("data     : %T %d %t\n", data, len(data), data == nil)
+	fmt.Printf("ratios   : %T %d %t\n", ratios, len(ratios), ratios == nil)
+	fmt.Printf("alives   : %T %d %t\n", alives, len(alives), alives == nil)
+}
--- a/16-slices/exercises/02-empty/main.go
+++ b/16-slices/exercises/02-empty/main.go
@ -0,0 +1,41 @@
+// 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"
+
+// ---------------------------------------------------------
+// EXERCISE: Assign empty slices
+//
+//   Assign empty slices to all the slices that you've declared in the previous
+//   exercise, and print them here.
+//
+//
+// EXPECTED OUTPUT
+//  names    : []string 0 false
+//  distances: []int 0 false
+//  data     : []uint8 0 false
+//  ratios   : []float64 0 false
+//  alives   : []bool 0 false
+// ---------------------------------------------------------
+
+func main() {
+	var (
+		names     []string  // The names of your friends
+		distances []int     // The distances
+		data      []byte    // A data buffer
+		ratios    []float64 // Currency exchange ratios
+		alives    []bool    // Up/Down status of web servers
+	)
+
+	fmt.Printf("names    : %T %d %t\n", names, len(names), names == nil)
+	fmt.Printf("distances: %T %d %t\n", distances, len(distances), distances == nil)
+	fmt.Printf("data     : %T %d %t\n", data, len(data), data == nil)
+	fmt.Printf("ratios   : %T %d %t\n", ratios, len(ratios), ratios == nil)
+	fmt.Printf("alives   : %T %d %t\n", alives, len(alives), alives == nil)
+}
--- a/16-slices/exercises/02-empty/solution/main.go
+++ b/16-slices/exercises/02-empty/solution/main.go
@ -0,0 +1,32 @@
+// 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"
+
+func main() {
+	var (
+		names     []string  // The names of your friends
+		distances []int     // The distances
+		data      []byte    // A data buffer
+		ratios    []float64 // Currency exchange ratios
+		alives    []bool    // Up/Down status of web servers
+	)
+
+	names = []string{}
+	distances = []int{}
+	data = []byte{}
+	ratios = []float64{}
+	alives = []bool{}
+
+	fmt.Printf("names    : %T %d %t\n", names, len(names), names == nil)
+	fmt.Printf("distances: %T %d %t\n", distances, len(distances), distances == nil)
+	fmt.Printf("data     : %T %d %t\n", data, len(data), data == nil)
+	fmt.Printf("ratios   : %T %d %t\n", ratios, len(ratios), ratios == nil)
+	fmt.Printf("alives   : %T %d %t\n", alives, len(alives), alives == nil)
+}
--- a/16-slices/exercises/03-slice-literal/main.go
+++ b/16-slices/exercises/03-slice-literal/main.go
@ -0,0 +1,63 @@
+// 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"
+
+// ---------------------------------------------------------
+// EXERCISE: Assign slice literals
+//
+//   1. Assign the following data using slice literals to the slices that
+//      you've declared in the first exercise.
+//
+//    1. The names of your best three friends (to the names slice)
+//
+//    2. The distances to five different locations (to the distances slice)
+//
+//    3. Five bytes of data (to the data slice)
+//
+//    4. Two currency exchange ratios (to the ratios slice)
+//
+//    5. Up/Down status of four different web servers (to the alives slice)
+//
+//  2. Print their type, length and whether they're equal to nil value or not
+//
+//  3. Compare the length of the distances and the data slices; print a message
+//     if they are equal (use an if statement).
+//
+//
+// EXPECTED OUTPUT
+//  names    : []string 3 false
+//  distances: []int 5 false
+//  data     : []uint8 5 false
+//  ratios   : []float64 2 false
+//  alives   : []bool 4 false
+//  The length of the distances and the data slices are the same.
+// ---------------------------------------------------------
+
+func main() {
+	var (
+		names     []string  // The names of your friends
+		distances []int     // The distances
+		data      []byte    // A data buffer
+		ratios    []float64 // Currency exchange ratios
+		alives    []bool    // Up/Down status of web servers
+	)
+
+	names = []string{}
+	distances = []int{}
+	data = []byte{}
+	ratios = []float64{}
+	alives = []bool{}
+
+	fmt.Printf("names    : %T %d %t\n", names, len(names), names == nil)
+	fmt.Printf("distances: %T %d %t\n", distances, len(distances), distances == nil)
+	fmt.Printf("data     : %T %d %t\n", data, len(data), data == nil)
+	fmt.Printf("ratios   : %T %d %t\n", ratios, len(ratios), ratios == nil)
+	fmt.Printf("alives   : %T %d %t\n", alives, len(alives), alives == nil)
+}
--- a/16-slices/exercises/03-slice-literal/solution/main.go
+++ b/16-slices/exercises/03-slice-literal/solution/main.go
@ -0,0 +1,36 @@
+// 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"
+
+func main() {
+	var (
+		names     []string  // The names of your friends
+		distances []int     // The distances
+		data      []byte    // A data buffer
+		ratios    []float64 // Currency exchange ratios
+		alives    []bool    // Up/Down status of web servers
+	)
+
+	names = []string{"serpil", "ebru", "lina"}
+	distances = []int{100, 200, 300, 400, 500}
+	data = []byte{'I', 'N', 'A', 'N', 'C'}
+	ratios = []float64{3.14, 6.28}
+	alives = []bool{true, false, false, true}
+
+	fmt.Printf("names    : %T %d %t\n", names, len(names), names == nil)
+	fmt.Printf("distances: %T %d %t\n", distances, len(distances), distances == nil)
+	fmt.Printf("data     : %T %d %t\n", data, len(data), data == nil)
+	fmt.Printf("ratios   : %T %d %t\n", ratios, len(ratios), ratios == nil)
+	fmt.Printf("alives   : %T %d %t\n", alives, len(alives), alives == nil)
+
+	if len(distances) == len(data) {
+		fmt.Println("The length of the distances and the data slices are the same.")
+	}
+}
--- a/16-slices/exercises/04-declare-arrays-as-slices/main.go
+++ b/16-slices/exercises/04-declare-arrays-as-slices/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"
+
+// ---------------------------------------------------------
+// EXERCISE: Declare the arrays as slices
+//
+//   1. First run the following program as it is
+//
+//   2. Then change the array declarations to slice declarations
+//
+//   3. Observe whether anything changes or not (on the surface :)).
+//
+// EXPECTED OUTPUT
+//  names    : []string ["Einstein" "Tesla" "Shepard"]
+//  distances: []int [50 40 75 30 125]
+//  data     : []uint8 [72 69 76 76 79]
+//  ratios   : []float64 [3.14]
+//  alives   : []bool [true false true false]
+//  zero     : []uint8 []
+// ---------------------------------------------------------
+
+func main() {
+	names := [3]string{"Einstein", "Tesla", "Shepard"}
+	distances := [...]int{50, 40, 75, 30, 125}
+	data := [5]byte{'H', 'E', 'L', 'L', 'O'}
+	ratios := [1]float64{3.14145}
+	alives := [...]bool{true, false, true, false}
+	zero := [0]byte{}
+
+	fmt.Printf("names    : %[1]T %[1]q\n", names)
+	fmt.Printf("distances: %[1]T %[1]d\n", distances)
+	fmt.Printf("data     : %[1]T %[1]d\n", data)
+	fmt.Printf("ratios   : %[1]T %.2[1]f\n", ratios)
+	fmt.Printf("alives   : %[1]T %[1]t\n", alives)
+	fmt.Printf("zero     : %[1]T %[1]d\n", zero)
+}
--- a/16-slices/exercises/04-declare-arrays-as-slices/solution/main.go
+++ b/16-slices/exercises/04-declare-arrays-as-slices/solution/main.go
@ -0,0 +1,26 @@
+// 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"
+
+func main() {
+	names := []string{"Einstein", "Tesla", "Shepard"}
+	distances := []int{50, 40, 75, 30, 125}
+	data := []byte{'H', 'E', 'L', 'L', 'O'}
+	ratios := []float64{3.14145}
+	alives := []bool{true, false, true, false}
+	zero := []byte{}
+
+	fmt.Printf("names    : %[1]T %[1]q\n", names)
+	fmt.Printf("distances: %[1]T %[1]d\n", distances)
+	fmt.Printf("data     : %[1]T %[1]d\n", data)
+	fmt.Printf("ratios   : %[1]T %.2[1]f\n", ratios)
+	fmt.Printf("alives   : %[1]T %[1]t\n", alives)
+	fmt.Printf("zero     : %[1]T %[1]d\n", zero)
+}
--- a/16-slices/exercises/05-fix-the-problems/main.go
+++ b/16-slices/exercises/05-fix-the-problems/main.go
@ -0,0 +1,57 @@
+// 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: Fix the problems
+//
+//  1. Uncomment the code
+//
+//  2. Fix the problems
+//
+//  3. BONUS: Simplify the code
+//
+//
+// EXPECTED OUTPUT
+//   "Einstein and Shepard and Tesla"
+//   ["Fire" "Kafka's Revenge" "Stay Golden"]
+//   [1 2 3 5 6 7 8 9]
+// ---------------------------------------------------------
+
+func main() {
+	// var names []string
+	// names := []string{}
+	// names = [...]string{
+	// 	"Einstein" "Shepard"
+	// 	"Tesla"
+	// }
+
+	// -----------------------------------
+	// var books []string = [3]string{
+	// 	"Stay Golden",
+	// 	"Fire",
+	// 	"Kafka's Revenge",
+	// }
+
+	// sort.Strings(books)
+
+	// -----------------------------------
+	// // this time, do not change the nums array to a slice
+	// nums := [...]int{5,1,7,3,8,2,6,9}
+
+	// // use the slicing expression to change the nums array to a slice below
+	// sort.Ints(nums)
+
+	// -----------------------------------
+	// Here: Use the strings.Join function to join the names
+	//       (see the expected output)
+	// fmt.Printf("%q\n", names)
+
+	// fmt.Printf("%q\n", books)
+	// fmt.Printf("%d\n", nums)
+}
--- a/16-slices/exercises/05-fix-the-problems/solution/main.go
+++ b/16-slices/exercises/05-fix-the-problems/solution/main.go
@ -0,0 +1,28 @@
+// 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"
+	"sort"
+	"strings"
+)
+
+func main() {
+	names := []string{"Einstein", "Shepard", "Tesla"}
+
+	books := []string{"Stay Golden", "Fire", "Kafka's Revenge"}
+	sort.Strings(books)
+
+	nums := [...]int{5, 1, 7, 3, 8, 2, 6, 9}
+	sort.Ints(nums[:])
+
+	fmt.Printf("%q\n", strings.Join(names, " and "))
+	fmt.Printf("%q\n", books)
+	fmt.Printf("%d\n", nums)
+}
--- a/16-slices/exercises/06-compare-the-slices/main.go
+++ b/16-slices/exercises/06-compare-the-slices/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
+
+// ---------------------------------------------------------
+// EXERCISE: Compare the slices
+//
+//  1. Split the namesA string and get a slice
+//
+//  2. Sort all the slices
+//
+//  3. Compare whether the slices are equal or not
+//
+//
+// EXPECTED OUTPUT
+//
+//   They are equal.
+//
+//
+// HINTS
+//
+//   1. strings.Split function splits a string and
+//      returns a string slice
+//
+//   2. Comparing slices: First check whether their length
+//      are the same or not; only then compare them.
+//
+// ---------------------------------------------------------
+
+func main() {
+	// namesA := "Da Vinci, Wozniak, Carmack"
+	// namesB := []string{"Wozniak", "Da Vinci", "Carmack"}
+}
--- a/16-slices/exercises/06-compare-the-slices/solution/main.go
+++ b/16-slices/exercises/06-compare-the-slices/solution/main.go
@ -0,0 +1,33 @@
+// 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"
+	"sort"
+	"strings"
+)
+
+func main() {
+	namesA := "Da Vinci, Wozniak, Carmack"
+	namesB := []string{"Wozniak", "Da Vinci", "Carmack"}
+
+	namesC := strings.Split(namesA, ", ")
+
+	sort.Strings(namesC)
+	sort.Strings(namesB)
+
+	if len(namesC) == len(namesB) {
+		for i := range namesC {
+			if namesC[i] != namesB[i] {
+				return
+			}
+		}
+		fmt.Println("They are equal.")
+	}
+}
--- a/16-slices/exercises/07-append/main.go
+++ b/16-slices/exercises/07-append/main.go
@ -0,0 +1,25 @@
+package main
+
+// ---------------------------------------------------------
+// EXERCISE: Append
+//
+//  Please follow the instructions within the code below.
+//
+// EXPECTED OUTPUT
+//  They are equal.
+//
+// HINTS
+//  bytes.Equal function allows you to compare two byte
+//  slices easily. Check its documentation: go doc bytes.Equal
+// ---------------------------------------------------------
+
+func main() {
+	// 1. uncomment the code below
+	// png, header := []byte{'P', 'N', 'G'}, []byte{}
+
+	// 2. append elements to header to make it equal with the png slice
+
+	// 3. compare the slices using the bytes.Equal function
+
+	// 4. print whether they're equal or not
+}
--- a/16-slices/exercises/07-append/solution/main.go
+++ b/16-slices/exercises/07-append/solution/main.go
@ -0,0 +1,23 @@
+// 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 (
+	"bytes"
+	"fmt"
+)
+
+func main() {
+	png, header := []byte{'P', 'N', 'G'}, []byte{}
+
+	header = append(header, png...)
+
+	if bytes.Equal(png, header) {
+		fmt.Println("They are equal")
+	}
+}
--- a/16-slices/exercises/08-append-2/main.go
+++ b/16-slices/exercises/08-append-2/main.go
@ -0,0 +1,41 @@
+package main
+
+// ---------------------------------------------------------
+// EXERCISE: Append #2
+//
+//  1. Create the following nil slices:
+//     + Pizza toppings
+//     + Departure times
+//     + Student graduation years
+//     + On/off states of lights in a room
+//
+//  2. Append them some elements (use your creativity!)
+//
+//  3. Print all the slices
+//
+//
+// EXPECTED OUTPUT
+// (Your output may change, mine is like so:)
+//
+//  pizza       : [pepperoni onions extra cheese]
+//
+//  graduations : [1998 2005 2018]
+//
+//  departures  : [2019-01-28 15:09:31.294594 +0300 +03 m=+0.000325020
+//  2019-01-29 15:09:31.294594 +0300 +03 m=+86400.000325020
+//  2019-01-30 15:09:31.294594 +0300 +03 m=+172800.000325020]
+//
+//  lights      : [true false true]
+//
+//
+// HINTS
+//  + For departure times, use the time.Time type. Check its documentation.
+//
+//      now := time.Now()     -> Gives you the current time
+//      now.Add(time.Hour*24) -> Gives you a time.Time 24 hours after `now`
+//
+//  + For graduation years, you can use the int type
+// ---------------------------------------------------------
+
+func main() {
+}
--- a/16-slices/exercises/08-append-2/solution/main.go
+++ b/16-slices/exercises/08-append-2/solution/main.go
@ -0,0 +1,55 @@
+// 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"
+	"time"
+)
+
+func main() {
+	// ------------------------------------------------------------
+	// Create nil slices
+	// ------------------------------------------------------------
+
+	// Pizza toppings
+	var pizza []string
+
+	// Departure times
+	var departures []time.Time
+
+	// Student graduation years
+	var grads []int
+
+	// On/off states of lights in a room
+	var lights []bool
+
+	// ------------------------------------------------------------
+	// Append them some elements (use your creativity!)
+	// ------------------------------------------------------------
+	pizza = append(pizza, "pepperoni", "onions", "extra cheese")
+
+	now := time.Now()
+	departures = append(departures,
+		now,
+		now.Add(time.Hour*24), // 24 hours after `now`
+		now.Add(time.Hour*48)) // 48 hours after `now`
+
+	grads = append(grads, 1998, 2005, 2018)
+
+	lights = append(lights, true, false, true)
+
+	// ------------------------------------------------------------
+	// Print the slices
+	// ------------------------------------------------------------
+
+	fmt.Printf("pizza       : %s\n", pizza)
+	fmt.Printf("\ngraduations : %d\n", grads)
+	fmt.Printf("\ndepartures  : %s\n", departures)
+	fmt.Printf("\nlights      : %t\n", lights)
+}
--- a/16-slices/exercises/09-append-3-fix/main.go
+++ b/16-slices/exercises/09-append-3-fix/main.go
@ -0,0 +1,27 @@
+package main
+
+// ---------------------------------------------------------
+// EXERCISE: Append #3 — Fix the problems
+//
+//  Fix the problems in the code below.
+//
+// BONUS
+//
+//  Simplify the code.
+//
+// EXPECTED OUTPUT
+//
+//  toppings: [black olives green peppers onions extra cheese]
+//
+// ---------------------------------------------------------
+
+func main() {
+	// toppings := []int{"black olives", "green peppers"}
+
+	// var pizza [3]string
+	// append(pizza, ...toppings)
+	// pizza = append(toppings, "onions")
+	// toppings = append(pizza, extra cheese)
+
+	// fmt.Printf("pizza       : %s\n", pizza)
+}
--- a/16-slices/exercises/09-append-3-fix/solution/main.go
+++ b/16-slices/exercises/09-append-3-fix/solution/main.go
@ -0,0 +1,20 @@
+// 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"
+
+func main() {
+	toppings := []string{"black olives", "green peppers"}
+
+	var pizza []string
+	pizza = append(pizza, toppings...)
+	pizza = append(pizza, "onions", "extra cheese")
+
+	fmt.Printf("toppings: %s\n", pizza)
+}
--- a/16-slices/exercises/README.md
+++ b/16-slices/exercises/README.md
@ -0,0 +1,25 @@
+# Slice Exercises
+
+## Exercises Level I - Basics — Warm-Up
+
+1. **[Declare nil slices](https://github.com/inancgumus/learngo/tree/master/16-slices/exercises/01-declare-nil)**
+
+2. **[Assign empty slices](https://github.com/inancgumus/learngo/tree/master/16-slices/exercises/02-empty)**
+
+3. **[Assign slice literals](https://github.com/inancgumus/learngo/tree/master/16-slices/exercises/03-slice-literal)**
+
+4. **[Declare the arrays as slices](https://github.com/inancgumus/learngo/tree/master/16-slices/exercises/04-declare-arrays-as-slices)**
+
+5. **[Fix the Problems](https://github.com/inancgumus/learngo/tree/master/16-slices/exercises/05-fix-the-problems)**
+
+6. **[Compare the slices](https://github.com/inancgumus/learngo/tree/master/16-slices/exercises/06-compare-the-slices)**
+
+---
+
+## Exercises Level II - Appending
+
+1. **[Append #1 — Append and compare byte slices](https://github.com/inancgumus/learngo/tree/master/16-slices/exercises/07-append)**
+
+2. **[Append #2 — Append to a nil slice](https://github.com/inancgumus/learngo/tree/master/16-slices/exercises/08-append-2)**
+
+3. **[Append #3 — Fix the problems](https://github.com/inancgumus/learngo/tree/master/16-slices/exercises/09-append-3-fix)**