add: struct exercises and quiz
This commit is contained in:
Inanc Gumus
@ -64,7 +64,7 @@ func main() {
|
||||
p.total += visits
|
||||
|
||||
// You cannot assign to composite values
|
||||
// p.sum[name].count += visits
|
||||
// p.sum[domain].visits += visits
|
||||
|
||||
// create and assign a new copy of `visit`
|
||||
p.sum[domain] = result{
|
||||
|
||||
@ -1,19 +0,0 @@
|
||||
[x] what?
|
||||
[x] why?
|
||||
[x] struct type
|
||||
[x] struct literal
|
||||
[x] anonymous structs
|
||||
[x] named structs
|
||||
[x] struct fields
|
||||
[x] compare and assign
|
||||
[x] printing
|
||||
[x] embedding
|
||||
[ ] exporting struct and fields
|
||||
[ ] struct tags {json encode/decode} - project?
|
||||
|
||||
**LATER:**
|
||||
[ ] funcs: constructor pattern
|
||||
[ ] pointers:
|
||||
[ ] structs and pointers - later
|
||||
[ ] padding and memory layout - later
|
||||
[ ] using anonymous structs when testing
|
||||
@ -1,21 +0,0 @@
|
||||
// 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: ??
|
||||
//
|
||||
//
|
||||
// EXPECTED OUTPUT
|
||||
//
|
||||
//
|
||||
// ---------------------------------------------------------
|
||||
|
||||
func main() {
|
||||
|
||||
}
|
||||
@ -1,12 +0,0 @@
|
||||
// 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
|
||||
|
||||
func main() {
|
||||
|
||||
}
|
||||
39
24-structs/exercises/01-warmup/main.go
Normal file
39
24-structs/exercises/01-warmup/main.go
Normal file
@ -0,0 +1,39 @@
|
||||
// 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: Warm Up
|
||||
//
|
||||
// Starting with this exercise, you'll build a command-line
|
||||
// game store.
|
||||
//
|
||||
// 1. Declare the following structs:
|
||||
//
|
||||
// + item: id (int), name (string), price (int)
|
||||
//
|
||||
// + game: embed the item, genre (string)
|
||||
//
|
||||
//
|
||||
// 2. Create a game slice using the following data:
|
||||
//
|
||||
// id name price genre
|
||||
//
|
||||
// 1 god of war 50 action adventure
|
||||
// 2 x-com 2 30 strategy
|
||||
// 3 minecraft 20 sandbox
|
||||
//
|
||||
//
|
||||
// 3. Print all the games.
|
||||
//
|
||||
// EXPECTED OUTPUT
|
||||
// Please run the solution to see the output.
|
||||
// ---------------------------------------------------------
|
||||
|
||||
func main() {
|
||||
}
|
||||
39
24-structs/exercises/01-warmup/solution/main.go
Normal file
39
24-structs/exercises/01-warmup/solution/main.go
Normal file
@ -0,0 +1,39 @@
|
||||
// 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() {
|
||||
type item struct {
|
||||
id int
|
||||
name string
|
||||
price int
|
||||
}
|
||||
|
||||
type game struct {
|
||||
item
|
||||
genre string
|
||||
}
|
||||
|
||||
games := []game{
|
||||
{
|
||||
item: item{id: 1, name: "god of war", price: 50},
|
||||
genre: "action adventure",
|
||||
},
|
||||
{item: item{id: 2, name: "x-com 2", price: 40}, genre: "strategy"},
|
||||
{item: item{id: 3, name: "minecraft", price: 20}, genre: "sandbox"},
|
||||
}
|
||||
|
||||
fmt.Printf("Inanc's game store has %d games.\n\n", len(games))
|
||||
|
||||
for _, g := range games {
|
||||
fmt.Printf("#%d: %-15q %-20s $%d\n",
|
||||
g.id, g.name, "("+g.genre+")", g.price)
|
||||
}
|
||||
}
|
||||
33
24-structs/exercises/02-list/main.go
Normal file
33
24-structs/exercises/02-list/main.go
Normal file
@ -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
|
||||
|
||||
// ---------------------------------------------------------
|
||||
// EXERCISE: List
|
||||
//
|
||||
// Now, it's time to add an interface to your program using
|
||||
// the bufio.Scanner. So the users can list the games, or
|
||||
// search for the games by id.
|
||||
//
|
||||
// 1. Scan for the input in a loop (use bufio.Scanner)
|
||||
//
|
||||
// 2. Print the available commands.
|
||||
//
|
||||
// 3. Implement the quit command: Quits from the loop.
|
||||
//
|
||||
// 4. Implement the list command: Lists all the games.
|
||||
//
|
||||
//
|
||||
// EXPECTED OUTPUT
|
||||
// Please run the solution and try the program with list and
|
||||
// quit commands.
|
||||
// ---------------------------------------------------------
|
||||
|
||||
func main() {
|
||||
// use your solution from the previous exercise
|
||||
}
|
||||
65
24-structs/exercises/02-list/solution/main.go
Normal file
65
24-structs/exercises/02-list/solution/main.go
Normal file
@ -0,0 +1,65 @@
|
||||
// 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 (
|
||||
"bufio"
|
||||
"fmt"
|
||||
"os"
|
||||
)
|
||||
|
||||
func main() {
|
||||
type item struct {
|
||||
id int
|
||||
name string
|
||||
price int
|
||||
}
|
||||
|
||||
type game struct {
|
||||
item
|
||||
genre string
|
||||
}
|
||||
|
||||
games := []game{
|
||||
{
|
||||
item: item{id: 1, name: "god of war", price: 50},
|
||||
genre: "action adventure",
|
||||
},
|
||||
{item: item{id: 2, name: "x-com 2", price: 40}, genre: "strategy"},
|
||||
{item: item{id: 3, name: "minecraft", price: 20}, genre: "sandbox"},
|
||||
}
|
||||
|
||||
fmt.Printf("Inanc's game store has %d games.\n", len(games))
|
||||
|
||||
in := bufio.NewScanner(os.Stdin)
|
||||
for {
|
||||
fmt.Printf(`
|
||||
> list : lists all the games
|
||||
> quit : quits
|
||||
|
||||
`)
|
||||
|
||||
if !in.Scan() {
|
||||
break
|
||||
}
|
||||
|
||||
fmt.Println()
|
||||
|
||||
switch in.Text() {
|
||||
case "quit":
|
||||
fmt.Println("bye!")
|
||||
return
|
||||
|
||||
case "list":
|
||||
for _, g := range games {
|
||||
fmt.Printf("#%d: %-15q %-20s $%d\n",
|
||||
g.id, g.name, "("+g.genre+")", g.price)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
47
24-structs/exercises/03-query-by-id/main.go
Normal file
47
24-structs/exercises/03-query-by-id/main.go
Normal file
@ -0,0 +1,47 @@
|
||||
// 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: Query By Id
|
||||
//
|
||||
// Add a new command: "id". So the users can query the games
|
||||
// by id.
|
||||
//
|
||||
// 1. Before the loop, index the games by id (use a map).
|
||||
//
|
||||
// 2. Add the "id" command.
|
||||
// When a user types: id 2
|
||||
// It should print only the game with id: 2.
|
||||
//
|
||||
// 3. Handle the errors:
|
||||
//
|
||||
// id
|
||||
// wrong id
|
||||
//
|
||||
// id HEY
|
||||
// wrong id
|
||||
//
|
||||
// id 10
|
||||
// sorry. i don't have the game
|
||||
//
|
||||
// id 1
|
||||
// #1: "god of war" (action adventure) $50
|
||||
//
|
||||
// id 2
|
||||
// #2: "x-com 2" (strategy) $40
|
||||
//
|
||||
//
|
||||
// EXPECTED OUTPUT
|
||||
// Please also run the solution and try the program with
|
||||
// list, quit, and id commands to see it in action.
|
||||
// ---------------------------------------------------------
|
||||
|
||||
func main() {
|
||||
// use your solution from the previous exercise
|
||||
}
|
||||
100
24-structs/exercises/03-query-by-id/solution/main.go
Normal file
100
24-structs/exercises/03-query-by-id/solution/main.go
Normal file
@ -0,0 +1,100 @@
|
||||
// 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 (
|
||||
"bufio"
|
||||
"fmt"
|
||||
"os"
|
||||
"strconv"
|
||||
"strings"
|
||||
)
|
||||
|
||||
func main() {
|
||||
type item struct {
|
||||
id int
|
||||
name string
|
||||
price int
|
||||
}
|
||||
|
||||
type game struct {
|
||||
item
|
||||
genre string
|
||||
}
|
||||
|
||||
games := []game{
|
||||
{
|
||||
item: item{id: 1, name: "god of war", price: 50},
|
||||
genre: "action adventure",
|
||||
},
|
||||
{item: item{id: 2, name: "x-com 2", price: 40}, genre: "strategy"},
|
||||
{item: item{id: 3, name: "minecraft", price: 20}, genre: "sandbox"},
|
||||
}
|
||||
|
||||
// index the games by id
|
||||
byID := make(map[int]game)
|
||||
for _, g := range games {
|
||||
byID[g.id] = g
|
||||
}
|
||||
|
||||
fmt.Printf("Inanc's game store has %d games.\n", len(games))
|
||||
|
||||
in := bufio.NewScanner(os.Stdin)
|
||||
for {
|
||||
fmt.Printf(`
|
||||
> list : lists all the games
|
||||
> id N : queries a game by id
|
||||
> quit : quits
|
||||
|
||||
`)
|
||||
|
||||
if !in.Scan() {
|
||||
break
|
||||
}
|
||||
|
||||
fmt.Println()
|
||||
|
||||
cmd := strings.Fields(in.Text())
|
||||
if len(cmd) == 0 {
|
||||
continue
|
||||
}
|
||||
|
||||
switch cmd[0] {
|
||||
case "quit":
|
||||
fmt.Println("bye!")
|
||||
return
|
||||
|
||||
case "list":
|
||||
for _, g := range games {
|
||||
fmt.Printf("#%d: %-15q %-20s $%d\n",
|
||||
g.id, g.name, "("+g.genre+")", g.price)
|
||||
}
|
||||
|
||||
case "id":
|
||||
if len(cmd) != 2 {
|
||||
fmt.Println("wrong id")
|
||||
continue
|
||||
}
|
||||
|
||||
id, err := strconv.Atoi(cmd[1])
|
||||
if err != nil {
|
||||
fmt.Println("wrong id")
|
||||
continue
|
||||
}
|
||||
|
||||
g, ok := byID[id]
|
||||
if !ok {
|
||||
fmt.Println("sorry. i don't have the game")
|
||||
continue
|
||||
}
|
||||
|
||||
fmt.Printf("#%d: %-15q %-20s $%d\n",
|
||||
g.id, g.name, "("+g.genre+")", g.price)
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -1,5 +1,15 @@
|
||||
# Structs Exercises
|
||||
# Struct Exercises
|
||||
|
||||
## Warm-Up
|
||||
You'll build a queryable command-line game store.
|
||||
|
||||
1. **[?](https://github.com/inancgumus/learngo/tree/master/???)**
|
||||
1. **[Warm Up](https://github.com/inancgumus/learngo/tree/master/24-structs/exercises/01-warmup)**
|
||||
|
||||
Load up the data into the game store.
|
||||
|
||||
2. **[List](https://github.com/inancgumus/learngo/tree/master/24-structs/exercises/02-list)**
|
||||
|
||||
Now, it's time to add an interface to your program using the bufio.Scanner. So the users can list the games, or search for the games by id.
|
||||
|
||||
3. **[Query By Id](https://github.com/inancgumus/learngo/tree/master/24-structs/exercises/03-query-by-id)**
|
||||
|
||||
Add a new command: "id". So the users can query the games by id.
|
||||
178
24-structs/questions/README.md
Normal file
178
24-structs/questions/README.md
Normal file
@ -0,0 +1,178 @@
|
||||
## When should you use a struct type?
|
||||
1. For storing the same type of values
|
||||
2. For adding an additional type of values in runtime
|
||||
3. For combining different types in a single type to represent a concept *CORRECT*
|
||||
|
||||
> **1:** Arrays, slices, and maps are better candidates for that.
|
||||
>
|
||||
> **2:** Struct fields are fixed at compile-time, you cannot add additional fields in runtime, neither you can remove them.
|
||||
>
|
||||
> **3:** That's right. A struct type combines different types of fields in a single type. You can use a struct type to represent a concept.
|
||||
>
|
||||
|
||||
|
||||
## What are the properties of struct fields?
|
||||
1. They all should be of the same type
|
||||
2. Each one should have a name and possibly a different type *CORRECT*
|
||||
3. You can add additional fields in runtime
|
||||
4. You can remove the existing fields in runtime
|
||||
|
||||
> **2:** Yes, each field should have a unique name. Also, each field should have a type, but every field can have a different type.
|
||||
>
|
||||
|
||||
|
||||
## What is wrong with the following code?
|
||||
```go
|
||||
type weather struct {
|
||||
temperature, humidity float64
|
||||
windSpeed float64
|
||||
temperature float64
|
||||
}
|
||||
```
|
||||
1. Nothing is wrong with it
|
||||
2. `temperature, humidity float64` field is a syntax error
|
||||
3. `temperature` field is not unique *CORRECT*
|
||||
|
||||
> **2:** That's a parallel definition. It defines two float64 fields: temperature and humidity. It is correct.
|
||||
>
|
||||
> **3:** Right! Struct field names should be unique.
|
||||
>
|
||||
|
||||
|
||||
## What is the zero-value of the following struct value?
|
||||
```go
|
||||
var movie struct {
|
||||
title, genre string
|
||||
rating float64
|
||||
released bool
|
||||
}
|
||||
```
|
||||
1. `{}`
|
||||
2. `{title: "", genre: "", rating: 0, released: false}` *CORRECT*
|
||||
3. `{title: "", genre: "", rating: 0, released: true}`
|
||||
4. `{"title, genre": "", rating: 0, released: false}`
|
||||
|
||||
> **1:** That's an empty struct value with no fields.
|
||||
>
|
||||
> **2:** Right! Go initializes a struct's fields to zero-values depending on their type.
|
||||
>
|
||||
|
||||
|
||||
|
||||
## What is the type of the following struct?
|
||||
```go
|
||||
avengers := struct {
|
||||
title, genre string
|
||||
rating float64
|
||||
released bool
|
||||
}{
|
||||
"avengers: end game", "sci-fi", 8.9, true,
|
||||
}
|
||||
|
||||
fmt.Printf("%T\n", avengers)
|
||||
```
|
||||
1. `struct{}`
|
||||
2. `struct{ string; string; float64; bool }`
|
||||
3. `struct{ title string; genre string; rating float64; released bool }` *CORRECT*
|
||||
4. `{title: "avengers: end game"; genre: "sci-fi"; rating: 8.9; released: true}`
|
||||
|
||||
> **1:** That's an empty struct type with no fields.
|
||||
>
|
||||
> **2:** Fields names is also a part of a struct's type.
|
||||
>
|
||||
> **3:** Right! Field names and types are part of a struct's type.
|
||||
>
|
||||
> **4:** Nope, that's a struct value.
|
||||
>
|
||||
|
||||
|
||||
## Are the following struct values equal?
|
||||
```go
|
||||
type movie struct {
|
||||
title, genre string
|
||||
rating float64
|
||||
released bool
|
||||
}
|
||||
|
||||
avengers := movie{"avengers: end game", "sci-fi", 8.9, true}
|
||||
clone := movie{
|
||||
title: "avengers: end game", genre: "sci-fi",
|
||||
rating: 8.9, released: true,
|
||||
}
|
||||
```
|
||||
1. There is a syntax error
|
||||
2. Yes *CORRECT*
|
||||
3. No
|
||||
|
||||
> **2:** When creating a struct value, it doesn't matter whether you use the field names or not. So, they are equal.
|
||||
>
|
||||
|
||||
|
||||
|
||||
## Are the following struct values equal? If not, why?
|
||||
```go
|
||||
type movie struct {
|
||||
title, genre string
|
||||
rating float64
|
||||
released bool
|
||||
}
|
||||
|
||||
avengers := movie{
|
||||
title: "avengers: end game", genre: "sci-fi",
|
||||
rating: 8.9, released: true,
|
||||
}
|
||||
|
||||
clone := movie{title: "avengers: end game", genre: "sci-fi"}
|
||||
|
||||
fmt.Println(avengers == clone)
|
||||
```
|
||||
1. Yes: They have the same set of fields
|
||||
2. No : They are not comparable
|
||||
3. No : Field values are different *CORRECT*
|
||||
|
||||
> **1:** That's right, this means they are comparable, but that's not enough.
|
||||
>
|
||||
> **2:** Yes, they are. They use the same struct type.
|
||||
>
|
||||
> **3:** Yes, when you omit some of the fields, Go assigns zero values to them. Here, "clone" struct value's "rating" and "released" fields are: 0, and false, respectively.
|
||||
>
|
||||
|
||||
|
||||
## Do the movie and performance struct types have the same types?
|
||||
```go
|
||||
type item struct { title string }
|
||||
type movie struct { item }
|
||||
type performance struct { item }
|
||||
```
|
||||
1. Yes: They have the same set of fields
|
||||
2. No : They have different type names *CORRECT*
|
||||
3. No : An embedded field cannot be compared
|
||||
|
||||
> **2:** Right! Types with different names cannot be compared. However, you can convert one of them to the other because they have the same set of fields. movie{} == movie(performance{}) is ok, or vice versa.
|
||||
>
|
||||
|
||||
|
||||
## What does the program print?
|
||||
```go
|
||||
type item struct{ title string }
|
||||
|
||||
type movie struct {
|
||||
item
|
||||
title string
|
||||
}
|
||||
|
||||
m := movie{
|
||||
title: "avengers: end game",
|
||||
item: item{"midnight in paris"},
|
||||
}
|
||||
|
||||
fmt.Println(m.title, "&", m.item.title)
|
||||
```
|
||||
1. midnight in paris & midnight in paris
|
||||
2. avengers: end game & avengers: end game
|
||||
3. midnight in paris & avengers: end game
|
||||
4. avengers: end game & midnight in paris *CORRECT*
|
||||
|
||||
> **4:** Right! `m.title` returns "avengers: end game" because the outer type always takes priority. However, `m.item.title` returns "midnight in paris" because you explicitly get it from the inner type: item.
|
||||
>
|
||||
|
||||
@ -32,8 +32,8 @@ func (s *Session) Start(transfers ...Transfer) <-chan Progress {
|
||||
|
||||
for _, t := range transfers {
|
||||
go func(t Transfer) {
|
||||
defer wg.Done()
|
||||
t.Start(updates, s.done)
|
||||
wg.Done()
|
||||
}(t)
|
||||
}
|
||||
|
||||
|
||||
Reference in New Issue
Block a user