Named return values in Go - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a function with named return values.

Go

func greet() (message string) {
    message = "Hello, Go!"
    return [1]
}

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

Amessage

Bgreet

Cstring

Dmsg

Attempts:

3 left

💡 Hint

Common Mistakes

Returning a variable not declared as a named return value.

Returning the function name instead of the variable.

The function uses a named return value message. Returning message returns the named value.

2fill in blank

medium

Complete the code to use named return values and omit the return expression.

Go

func add(a, b int) (sum int) {
    sum = a + b
    [1]
}

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

Areturn sum

Breturn a + b

Creturn

Dreturn sum + 1

Attempts:

3 left

💡 Hint

Common Mistakes

Returning the variable explicitly when a bare return is enough.

Returning an incorrect expression.

When using named return values, a bare return returns the current values of those variables.

3fill in blank

hard

Fix the error in the function by completing the return statement correctly.

Go

func divide(a, b float64) (result float64, err error) {
    if b == 0 {
        err = fmt.Errorf("division by zero")
        [1]
    }
    result = a / b
    return
}

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

Areturn 0, err

Breturn result, nil

Creturn err, 0

Dreturn nil, err

Attempts:

3 left

💡 Hint

Common Mistakes

Returning error and result in wrong order.

Returning nil instead of zero for result.

When division by zero occurs, result should be zero and err should hold the error. So return 0, err.

4fill in blank

hard

Fill both blanks to complete the function with named return values and a bare return.

Go

func multiply(a, b int) (product int, err error) {
    if a < 0 || b < 0 {
        err = fmt.Errorf("negative input")
        [1]
    }
    product = a * b
    [2]
}

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

Areturn

Breturn product, err

Creturn 0, err

Dreturn err

Attempts:

3 left

💡 Hint

Common Mistakes

Using bare return in the error case without setting product to zero.

Returning only error without product.

If inputs are negative, return zero product and the error. Otherwise, assign product and use a bare return to return named values.

5fill in blank

hard

Fill all three blanks to complete the function using named return values and proper error handling.

Go

func subtract(a, b int) (result int, err error) {
    if a < b {
        err = fmt.Errorf("a is less than b")
        [1]
    }
    result = a - b
    [2]
    [3]
}

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

Areturn 0, err

Breturn

Creturn result, err

Dreturn err

Attempts:

3 left

💡 Hint

Common Mistakes

Returning error only without result.

Not using bare return after assigning result.

When a < b, return zero and error. Otherwise, assign result and use bare return twice (the second bare return is redundant but included for the exercise).