Returning errors in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to return an error from the function.

Go

func check(value int) error {
    if value < 0 {
        return [1]("negative value")
    }
    return nil
}

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

Aerrors.New

Bpanic

Clog.Fatal

Dfmt.Println

Attempts:

3 left

💡 Hint

Common Mistakes

Using fmt.Println instead of returning an error.

Using panic which stops the program instead of returning an error.

The errors.New function creates a new error with the given message, which can be returned.

2fill in blank

medium

Complete the code to declare the function returns an error.

Go

func divide(a, b int) (int, [1]) {
    if b == 0 {
        return 0, errors.New("division by zero")
    }
    return a / b, nil
}

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

Abool

Bint

Cerror

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Returning string instead of error.

Not declaring the error return type.

The function returns an int and an error type to indicate success or failure.

3fill in blank

hard

Fix the error in the code to properly return an error.

Go

func openFile(name string) error {
    f, err := os.Open(name)
    if err != nil {
        return [1]
    }
    defer f.Close()
    return nil
}

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

Aerr

Bf

Cnil

Dos.Open

Attempts:

3 left

💡 Hint

Common Mistakes

Returning the file handle f instead of the error.

Returning nil when there is an error.

When os.Open returns an error, it should be returned directly as err.

4fill in blank

hard

Fill both blanks to create and return a formatted error message.

Go

func validate(age int) error {
    if age < 18 {
        return fmt.Errorf([1], [2])
    }
    return nil
}

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

A"age %d is too young"

Bage

C"error"

Dfmt.Errorf

Attempts:

3 left

💡 Hint

Common Mistakes

Using a plain string without formatting.

Not passing the age variable to format the message.

fmt.Errorf formats the error message with the age value.

5fill in blank

hard

Fill all three blanks to check error and handle it properly.

Go

result, err := divide(10, 0)
if [1] != nil {
    fmt.Println([2])
} else {
    fmt.Println([3])
}

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

Aerr

Cresult

Dnil

Attempts:

3 left

💡 Hint

Common Mistakes

Checking the wrong variable for error.

Printing the error in the else block.

Check if err is not nil to handle errors, otherwise print the result.