Explore fun brain teasers to hone your logic, critical thinking, and problem-solving skills. Gain insights into Go and practice to avoid future mistakes.

go.tar.gz

Go lang

Who knew puzzles could be fun? Puzzles and brain teasers are a great way to practice your critical thinking and improve your logic and problem-solving skills. This course provides a basic understanding of Go. The teasers in this course will help you practice what you already know and help avoid future mistakes.

Go Brain Teasers

# Try it yourself ##

Try executing the code below to see the result for yourself.

package main

import (
	"fmt"
)

type Job struct {
	State string
	done  chan struct{}
}

func (j *Job) Wait() {
	<-j.done
}

func (j *Job) Done() {
	j.State = "done"
	close(j.done)
}

func main() {
	ch := make(chan Job)
	go func() {
		j := <-ch
		j.Done()
	}()

	job := Job{"ready", make(chan struct{})}
	ch <- job
	job.Wait()
	fmt.Println(job.State)
}




# Explanation ##

At first glance, the code looks fine. We’re using a pointer receiver in the `Job` struct methods. If the channel is closed, then the call to `Wait` is terminated. 

The problem is with the definition of `ch`. It is a channel for  `Job`, not `*Job`, which means that when we send the variable `job` over the channel, we send a copy of it. A channel in Go is a pointer-like type, so even though there is a copy of `job` inside the goroutine, `j.done` points to the same channel `job.done` is pointing to.




Before We Begin

Puzzles

Wrapping Up

Puzzle 18 Explanation: Go Job

Try it yourself

Explanation