add: questions for the loops section

2018-10-22 19:15:32 +03:00
parent 0205846da0
commit bd538864f3
4 changed files with 477 additions and 3 deletions
--- a/13-loops/questions/01-loops.md
+++ b/13-loops/questions/01-loops.md
@@ -0,0 +1,215 @@
+## Which one of these is a valid loop statement in Go?
+1. while
+2. forever
+3. until
+4. for *CORRECT*
+
+> **4:** Correct. There is only one loop statement in Go.
+
+
+## What does this code print?
+```go
+for i := 3; i > 0; i-- {
+    fmt.Println(i)
+}
+```
+1. 3 2 1 *CORRECT*
+2. 1 2 3
+3. 0 1 2
+4. 2 1 0
+
+
+## What does this code print?
+```go
+for i := 3; i > 0; {
+    i--
+    fmt.Println(i)
+}
+```
+1. 3 2 1
+2. 1 2 3
+3. 0 1 2
+4. 2 1 0 *CORRECT*
+
+
+## What does this code print?
+```go
+for i := 3; ; {
+    if i <= 0 {
+        break
+    }
+
+    i--
+    fmt.Println(i)
+}
+```
+1. 3 2 1
+2. 1 2 3
+3. 0 1 2
+4. 2 1 0 *CORRECT*
+
+
+## What does this code print?
+```go
+for i := 2; i <= 9; i++ {
+    if i % 3 != 0 {
+        continue
+    }
+
+    fmt.Println(i)
+}
+```
+1. 3 6 9 *CORRECT*
+2. 9 6 3
+3. 2 3 6 9
+4. 2 3 4 5 6 7 8 9
+
+
+## How can you simplify this code?
+```go
+for ; true ; {
+    // ...
+}
+```
+1. ```go
+   for true {
+   }
+   ```
+2. ```go
+   for true; {
+   }
+   ```
+3. ```go
+   for {
+   }
+   ```
+   *CORRECT*
+4. ```go
+   for ; true {
+   }
+   ```
+
+
+## What does this code print?
+Let's say that you run the program like this:
+```bash
+go run main.go go is awesome
+```
+
+```go
+for i, v := range os.Args {
+    fmt.Println(i+1, v)
+}
+```
+1. ```
+   1 go
+   2 is
+   3 awesome
+   ```
+   *CORRECT*
+2. ```
+   go
+   is
+   awesome
+   ```
+3. ```
+   0 go
+   1 is
+   2 awesome
+   ```
+4. ```
+   1
+   2
+   3
+   ```
+
+
+## What does this code print?
+Let's say that you run the program like this:
+```bash
+go run main.go go is awesome
+```
+
+```go
+for i := range os.Args {
+    fmt.Println(i+1)
+}
+```
+1. ```
+   1 go
+   2 is
+   3 awesome
+   ```
+2. ```
+   go
+   is
+   awesome
+   ```
+3. ```
+   0 go
+   1 is
+   2 awesome
+   ```
+4. ```
+   1
+   2
+   3
+   ```
+   *CORRECT*
+
+
+## What does this code print?
+Let's say that you run the program like this:
+```bash
+go run main.go go is awesome
+```
+
+```go
+for _, v := range os.Args {
+    fmt.Println(v)
+}
+```
+1. ```
+   1 go
+   2 is
+   3 awesome
+   ```
+2. ```
+   go
+   is
+   awesome
+   ```
+   *CORRECT*
+3. ```
+   0 go
+   1 is
+   2 awesome
+   ```
+4. ```
+   1
+   2
+   3
+   ```
+
+
+## What does this code print?
+Let's say that you run the program like this:
+```bash
+go run main.go go is awesome
+```
+
+```go
+var i int
+
+for range os.Args {
+    i++
+}
+
+fmt.Println(i)
+```
+1. go is awesome
+2. 1 2 3
+3. 2
+4. 3 *CORRECT*
+
+> **4:** As you can see, you can also use a for range statement for counting things.