Sending and receiving values in Go - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a channel in Go?

A channel is a way to send and receive values between goroutines safely and synchronously.

beginner

How do you send a value to a channel in Go?

Use the syntax channel <- value to send a value into the channel.

beginner

How do you receive a value from a channel in Go?

Use the syntax value := <-channel to receive a value from the channel.

intermediate

What happens if you try to receive from an empty channel?

The receiving goroutine waits (blocks) until a value is sent to the channel.

intermediate

What happens if you try to send to a full buffered channel?

The sending goroutine waits (blocks) until there is space available in the channel buffer.

How do you send the integer 5 to a channel named ch in Go?

A send(ch, 5)

B 5 <- ch

C ch <- 5

D ch.send(5)

The correct syntax to send a value to a channel is channel <- value.

What does the expression value := <-ch do?

A Receives a value from channel ch and stores it in value

B Sends value to channel ch

C Closes the channel ch

D Creates a new channel ch

The syntax value := <-ch receives a value from channel ch.

What happens if you send to an unbuffered channel but no goroutine is ready to receive?

A The send operation fails immediately

B The send operation blocks until a receiver is ready

C The value is lost

D The channel buffers the value automatically

Unbuffered channels block the sender until a receiver is ready to receive.

Which of these is true about buffered channels?

A They never block on send

B They block on send only when the buffer is full

C They block on receive only when the buffer is empty

D Both B and D

Buffered channels block on send if full and block on receive if empty.

How do you declare a channel of integers in Go?

A var ch chan int

B var ch int chan

C chan int ch

D int chan ch

The correct declaration is var ch chan int.

Explain how sending and receiving values on channels works in Go.

Think about how goroutines communicate safely using channels.

Describe what happens when you send to or receive from a channel that is not ready.

Consider what happens if no goroutine is ready to receive or send.