GO Channels and Communication 2

Question 1

What is a directional channel type in Go?

Accepted Answer

A channel restricted to send-only or receive-only operations

Answer

Directional channels like `chan<- int` (send-only) and `<-chan int` (receive-only) restrict operations for safer API design.

Question 2

What does `select { case <-ch: default: }` do?

Accepted Answer

Performs a non-blocking receive from ch

Answer

A `select` with a `default` case performs a non-blocking operation; if no case is ready, `default` executes immediately.

Question 3

Which channel declaration creates an unbuffered channel of strings?

Accepted Answer

Both B and C

Answer

Both `make(chan string)` and `make(chan string, 0)` create unbuffered channels; `var ch chan string` declares a nil channel.

Question 4

What is a nil channel's behavior when read from or written to?

Accepted Answer

Blocks forever

Answer

Both sends and receives on a nil channel block forever, which can be used intentionally to disable a select case.

Question 5

How can you implement a timeout for a channel receive in Go?

Accepted Answer

Use select with a time.After case

Answer

`select { case v := <-ch: ... case <-time.After(d): ... }` implements a receive timeout by racing the channel against a timer channel.

GO - Golang Online Test Practice Test