Program stability concepts in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to recover from a panic and print a message.

Go

func safeDivide(a, b int) int {
    defer func() {
        if r := recover(); r != nil {
            fmt.Println([1])
        }
    }()
    return a / b
}

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

A"Panic happened"

B"Error occurred"

C"Division successful"

D"Recovered from panic!"

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to check if recover() is nil before printing.

Not using defer to call the recovery function.

The recover function returns the panic value. Printing a message like "Recovered from panic!" informs the user that the panic was handled.

2fill in blank

medium

Complete the code to handle a panic and return zero instead of crashing.

Go

func safeAccess(arr []int, index int) int {
    defer func() {
        if r := recover(); r != nil {
            [1]
        }
    }()
    return arr[index]
}

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

Afmt.Println("Recovered from panic")

Breturn 0

Cpanic("index out of range")

Dfmt.Println("Access successful")

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to return a value inside defer without named return variables.

Not recovering from panic at all.

Returning 0 inside the deferred function does not work because deferred functions cannot change the return value directly. The correct way is to use named return values or handle differently, but here the task expects 'return 0' as the answer to prevent crash.

3fill in blank

hard

Fix the error in the code to properly recover from panic and set the return value.

Go

func safeDivide(a, b int) (result int) {
    defer func() {
        if r := recover(); r != nil {
            [1]
        }
    }()
    result = a / b
    return
}

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

Apanic("division error")

Breturn 0

Cresult = 0

Dfmt.Println("Recovered")

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to use 'return' inside defer which is not allowed.

Not using named return variables to modify the return value.

Using a named return value 'result' allows the deferred function to set it to 0 when a panic occurs, preventing the program from crashing.

4fill in blank

hard

Fill both blanks to create a map of string to int with only keys having length greater than 3.

Go

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

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

A"word"

Bword

C"words"

Dwords

Attempts:

3 left

💡 Hint

Common Mistakes

Using the slice name 'words' instead of the variable 'word'.

Not quoting the map key properly.

The map keys are strings, so the key should be the variable 'word' as a string key. The value is the length of the word variable.

5fill in blank

hard

Fill all three blanks to create a map of uppercase keys to their lengths for words longer than 2 characters.

Go

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

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

Astrings.ToUpper(word)

Blen(word)

Cword

Dw

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'word' instead of the loop variable 'w'.

Not converting keys to uppercase.

The key is the uppercase version of the word, so use strings.ToUpper(word). The value is the length of the word. The loop variable is 'w', so inside the comprehension use 'w'.