robertBojor/go_test.md

## go_test.md

      
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              go_test.md
            
          
    Questions
1. What is the output of the following program?
package main
import "fmt"
type User struct {
	Name string
}
var user User
func main() {
	fmt.Println(user)
}

2. What is the output of the following program?
package main
import "fmt"

func main() {
 x := 1
 y := &x
 fmt.Println(*y)
 *y = 2
 fmt.Println(x)
}

3. What is the output of the following program?
package main
import "fmt"

func main() {
 defer func() { fmt.Println("A") }()
 go func() { fmt.Println("C") }()
 fmt.Println("B")
}

4. How can you achieve polymorphism in golang. Please provide a short example.
5. Enumerate some standard libraries and their usage.
6. Write a short function that return a read only channel.
7. Write a short example of data synchronization in go
8. Enumerate some go cli commands
9. How can you achieve cross-compiling?
10. Fix this code to print the output.
package main

import "fmt"
import "encoding/json"

type Event struct {
	Name string
	Data interface{}
}

var e Event = Event{"x", "y"}

func main() {
	str, _ := json.Marshal(e)
	fmt.Println(str)
}

EXPECTED OUTPUT: {"name":"x","data":"y"}


Exercice ( ± 60min )
Write a minimal thread pool using go routines and channels.
Requirements:

Use 3 workers
Program should receive a json file like following ['{URL_TO_IMAGE}', ...] as first param demo ./images.json
All files should be stored in ./data folder ( Create folder if missing )
For each download print the following:

#X - Downloading http://example.com/path-to-image...
#X - Completed http://example.com/path-to-image...


#X is the id of the thread number ( #1 - .... )

Done when:

A file name demo.go is provided
It successfully compiles
The binary output meets requirements