Basics

Question 1

What is special about a name with a capital letter?

Answer 1

It is an EXPORTED name.

Question 2

What denotes an exported name?

Answer 2

It starts with a capital letter.

Question 3

Every Go program is made up of ________.

Answer 3

packages

Question 4

What is the name of the package where every program starts?

Answer 4

main

Question 5

What kind of statement is used to make external packages accessible?

Answer 5

import

Question 6

How can the following statements be improved?

import "fmt" import "math"

Answer 6

By using a single, “factored” import statement:

import ( "fmt" "math" )

Question 7

What kind of statement is used to define a function?

Answer 7

func

Question 8

Can a function have zero arguments?

Answer 8

Yes

Question 9

How would you define a function named “factorial”, taking an integer argument “x” and returning an integer?

Answer 9

func factorial(x int) int { // ... }

Question 10

Is there anything wrong with this function definition?

func odd (x int) bool { // ... }

Answer 10

No

Question 11

Is there anything wrong with this function definition?

func odd (int x) bool { // ... }

Answer 11

Yes; the argument type specifier must come AFTER the argument name: func odd (x int) ...

Question 12

Consider this function:

func add(x, y int) int { return x + y }

What are the types for x and y? Why?

Answer 12

Both x and y are type “int”. The int after the argument list x, y applies to both arguments.

Question 13

What is the special purpose of the package name “main”?

Answer 13

All programs start in this package.

Question 14

Assuming a package named “ez” with a function named “Action”, how could this function be accessed from another package?

Answer 14

By importing the package with import "ez", then using the full name ez.Action.

Question 15

Assuming a package named “ez” with a function named “action”, how could this function be accessed from another package?

Answer 15

The function could not be accessed from outside the package because the name “action” does not start with a capital letter, thus it is not exported.

Question 16

Can a function return more than one result?

Answer 16

Yes

Question 17

How would you define a function named “swap”, taking two string arguments “x” and “y”, and returning two string arguments?

Answer 17

func swap(x, y string) (string, string) { // ... }

Question 18

How would you declare a package named “ez”?

Answer 18

With the statement package ez.

Question 19

Could the following function definition be improved?

func sum(x int, y int) int { // ... }

Answer 19

Yes, by shortening the argument declaration:

func sum(x, y int) int { // ... }

Question 20

Is there anything wrong with this package clause?

package "main"

Answer 20

Yes; the identifier main should not be quoted.

Question 21

Is there anything wrong with this package clause?

package main

Answer 21

No