Named return values in Go - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are named return values in Go?

Named return values are variables defined in a function's signature that hold the return values. They allow you to return values without explicitly specifying them in the return statement.

beginner

How do you declare named return values in a Go function?

You declare named return values by specifying variable names and types inside the parentheses after the function parameters, like: func example() (result int, err error).

intermediate

What happens if you use a bare return statement in a function with named return values?

A bare return returns the current values of the named return variables. This means you don't have to specify the variables explicitly in the return statement.

intermediate

Can named return values improve code readability? Why or why not?

Yes, named return values can improve readability by giving meaningful names to return values, making it clear what each returned value represents without needing extra comments.

beginner

Show a simple Go function using named return values to return the sum and difference of two integers.

Example:

func calc(a, b int) (sum int, diff int) {
    sum = a + b
    diff = a - b
    return
}

This function returns sum and diff without explicitly listing them in the return statement.

In Go, how do you define named return values in a function?

A By naming variables in the return type parentheses

B By declaring variables inside the function body

C By using global variables

D By using pointers only

Named return values are declared by naming variables in the return type parentheses of the function signature.

What does a bare return statement do in a function with named return values?

A Returns the current values of named return variables

B Returns zero values

C Causes a compile error

D Returns nothing

A bare return returns the current values of the named return variables without needing to specify them.

Which of the following is a benefit of using named return values?

A They allow multiple return types

B They improve code readability by naming return values

C They prevent runtime errors

D They make functions run faster

Named return values improve readability by giving meaningful names to the returned data.

What is the output of this Go function? func example() (x int) { x = 5 return } A call to example() returns:

A 0

B An error

C 5

D Undefined

The function sets x to 5 and returns it using a bare return, so the output is 5.

Can you mix named and unnamed return values in a Go function signature?

A Only if the function has one return value

B No, all must be named or unnamed

C Only in Go versions before 1.10

D Yes, but it's discouraged

You can mix named and unnamed return values, but it is generally discouraged for clarity.

Explain what named return values are in Go and how they affect the return statement.

Think about how naming return variables changes how you write return statements.

Write a simple Go function using named return values to return the quotient and remainder of two integers.

Use division and modulus operators and name the return values clearly.