Channel synchronization in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to send a value into the channel.

Go

ch := make(chan int)

func main() {
    go func() {
        ch[1] 42
    }()
    val := <-ch
    println(val)
}

Drag options to blanks, or click blank then click option'

A<-chan

B<-

C<-ch

D<-chan int

Attempts:

3 left

💡 Hint

Common Mistakes

Using the receive operator '<-' instead of the send operator.

Confusing channel type syntax with send/receive syntax.

To send a value into a channel in Go, use the syntax ch <- value.

2fill in blank

medium

Complete the code to receive a value from the channel.

Go

ch := make(chan string)

func main() {
    go func() {
        ch <- "hello"
    }()
    msg := [1]ch
    println(msg)
}

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A<-ch

B<-

Cch

Dchan

Attempts:

3 left

💡 Hint

Common Mistakes

Using the channel name alone without the receive operator.

Using the send operator instead of receive operator.

To receive a value from a channel, use the syntax value := <-ch.

3fill in blank

hard

Fix the error in the code to properly synchronize using a channel.

Go

done := make(chan bool)

func main() {
    go func() {
        println("Working...")
        [1] <- true
    }()
    <-done
}

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Adone

Bdone()

Cdone <-

D<-done

Attempts:

3 left

💡 Hint

Common Mistakes

Reversing the send operator direction.

Calling the channel as a function.

To send a value into the channel, use done <- true. The channel variable name must be on the left.

4fill in blank

hard

Fill both blanks to create a map of word lengths for words longer than 3 characters.

Go

words := []string{"go", "code", "chat", "ai"}
lengths := map[string]int{
    [1]: [2] for _, word := range words if len(word) > 3
}

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A"word"

Bword

Clen(word)

Dword.len()

Attempts:

3 left

💡 Hint

Common Mistakes

Using string literals as keys instead of variables.

Using incorrect method syntax like word.len().

The key should be the word itself, and the value should be its length using len(word).

5fill in blank

hard

Fill all three blanks to create a synchronized counter using a channel.

Go

counter := 0
increment := make(chan bool)

go func() {
    for {
        <-[1]
        [2]++
        println([3])
    }
}()

func main() {
    increment <- true
}

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Aincrement

Bcounter

Dincrement()

Attempts:

3 left

💡 Hint

Common Mistakes

Using function call syntax for the channel.

Mixing up variable names for counter and channel.

The channel to receive from is increment. The counter variable is incremented and printed.