GO Channels and Communication 3

Question 1

What is the fan-in concurrency pattern?

Accepted Answer

Multiple channels are merged into one output channel

Answer

Fan-in merges multiple input channels into a single output channel, typically using a goroutine per input channel that forwards values.

Question 2

How do you check if a channel receive returned a real value or a closed-channel zero value?

Accepted Answer

v, ok := <-ch; check ok

Answer

The two-value receive `v, ok := <-ch` sets `ok` to `false` when the channel is closed and all buffered values have been received.

Question 3

What does `len(ch)` return for a buffered channel?

Accepted Answer

Number of elements currently buffered

Answer

`len(ch)` returns the number of elements currently queued (unread) in the channel's buffer.

Question 4

What is a done channel pattern used for?

Accepted Answer

Signal goroutines to stop working and exit

Answer

A done channel (typically `chan struct{}`) is closed to broadcast a cancellation signal to multiple goroutines watching it.

Question 5

Why is `chan struct{}` preferred over `chan bool` for signaling in Go?

Accepted Answer

struct{} consumes zero bytes, minimizing memory overhead

Answer

`struct{}` is an empty type with zero size, so a `chan struct{}` uses no memory for the values themselves, making it the most efficient signal channel.

GO - Golang Online Test Practice Test

GO - Golang Online Test Practice Test

GO Channels and Communication 3