Return values in Go - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a return value in Go functions?

A return value is the output that a function sends back to the place where it was called. It lets the function give back a result after doing its work.

beginner

How do you declare a function in Go that returns an integer?

You write the function with the return type after the parameter list. For example:

func add(a int, b int) int { return a + b }

This function returns an int.

intermediate

Can a Go function return multiple values? Give an example.

Yes, Go functions can return multiple values. For example:

func divide(a, b int) (int, int) { return a / b, a % b }

This returns both quotient and remainder.

intermediate

What happens if a Go function does not have a return statement but declares a return type?

The Go compiler will give an error because the function promises to return a value but does not. Every path must return a value if a return type is declared.

advanced

Explain named return values in Go functions.

Named return values let you name the results in the function signature. Inside the function, you can set these names like variables and use a bare return to send them back. Example:<pre>func sumAndDiff(a, b int) (sum int, diff int) { sum = a + b; diff = a - b; return }</pre>

What does this Go function return?

func greet() string { return "Hello" }

A A string

B An integer

C Nothing

D A boolean

The function returns a string "Hello" as declared by the return type string.

How many values does this function return?

func values() (int, string) { return 5, "Go" }

A One

B Zero

C Three

D Two

The function returns two values: an int and a string.

What will happen if a function declares a return type but has no return statement?

A It compiles fine

B It causes a compile-time error

C It returns zero by default

D It returns nil

Go requires all functions with return types to have return statements; otherwise, it causes a compile-time error.

Which keyword is used to send back values from a Go function?

A return

B send

C yield

D output

The keyword 'return' is used to send back values from a function.

What is special about named return values in Go?

A They are deprecated

B They require explicit return values every time

C They allow returning values without specifying them in the return statement

D They are only used for error handling

Named return values let you set variables inside the function and use a bare return without specifying values explicitly.

Explain how return values work in Go functions and how to declare them.

Think about how functions send back results after running.

Describe named return values in Go and how they simplify returning multiple results.

It's like giving names to the boxes you will send back.