Default case in select in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a default case in the select statement.

Go

select {
case msg := <-ch:
    fmt.Println("Received:", msg)
[1]:
    fmt.Println("No message received")
}

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

Adefault

Bcase

Celse

Dfallback

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'case' instead of 'default' for the default case.

Using 'else' or 'fallback' which are not valid in select.

The default case in a select runs if no other case is ready.

2fill in blank

medium

Complete the code to print a message when no channel is ready using the default case.

Go

select {
case <-ch1:
    fmt.Println("ch1 ready")
case <-ch2:
    fmt.Println("ch2 ready")
[1]:
    fmt.Println("No channels ready")
}

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

Acase else

Bcase default

Celse

Ddefault

Attempts:

3 left

💡 Hint

Common Mistakes

Writing 'case default:' which is invalid syntax.

Using 'else' which is not a Go keyword in select.

The default keyword alone defines the default case in a select.

3fill in blank

hard

Fix the error in the select statement by completing the default case correctly.

Go

select {
case msg := <-ch:
    fmt.Println("Got message:", msg)
[1]:
    fmt.Println("No message received")
}

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

Acase default

Bdefault

Ccase else

Delse

Attempts:

3 left

💡 Hint

Common Mistakes

Writing 'case default:' which causes a syntax error.

Using 'else' which is not valid in select.

The default case in Go's select uses only the keyword default without 'case'.

4fill in blank

hard

Fill both blanks to create a select with two channel cases and a default case.

Go

select {
case msg1 := <-ch1:
    fmt.Println("ch1:", msg1)
case msg2 := <-ch2:
    fmt.Println("ch2:", msg2)
[1]:
    fmt.Println("[2]")
}

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

Adefault

Bcase

CNo channels ready

DNo message

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'case' before 'default' keyword.

Printing a wrong message.

The default case starts with default: and the print statement shows the message.

5fill in blank

hard

Fill all three blanks to write a select that reads from two channels and uses a default case with a message.

Go

select {
case val1 := <-chan1:
    fmt.Println("chan1 value:", [1])
case val2 := <-chan2:
    fmt.Println("chan2 value:", [2])
[3]:
    fmt.Println("No data received")
}

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

Aval1

Bval2

Cdefault

Dval3

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable names in print statements.

Writing 'case default' instead of 'default'.

Use the variables val1 and val2 to print channel values, and default for the default case.