Go

Question 1

In Go, every program is part of a…

Answer 1

Package

Question 2

What does the first line of code in Go program look like?

Answer 2

package main

Question 3

What lets us import files included in the fmt package?

Answer 3

import “fmt”

Question 4

What is considered white space?

Answer 4

Blank lines

Question 5

What is the purpose of leaving white space?

Answer 5

Makes code more readable

Question 6

What is func main() {

}
?

Answer 6

A function. Any code within the {} is executed.

Question 7

In Go, executable code belongs to what package?

Answer 7

main

Question 8

How are statements separated?

Answer 8

Ending a line by hitting enter key or by a semicolon “;”

Question 9

What is a comment?

Answer 9

Text that is ignored upon execution. Used to explain code and make it more readable.

They can be used to prevent code execution when testing an alternative code, as well.

Question 10

How are comments denoted?

Answer 10

// single line comments

/* multi line comments */

Question 11

What are the three basic data types? What do they represent?

Answer 11

bool: boolean values, true/false

Numeric: integer types, floating point values, and complex types

string: string values

Question 12

How do you declare a variable?

Answer 12

var variablename type = value

variablename := value

Question 13

:=

Answer 13

When this declaration is used, type of variable is inferred.

It’s not possible to declare a variable using := without assigning a value to it.

Question 14

What happens when a variable is declared without an initial value?

Answer 14

Values get set to default value of its type.

string = “ “
int = 0
bool = false

Question 15

Can you declare a variable using “:=“ without assigning a value to it?

Answer 15

No

Question 16

What is the difference between the var and := ?

Answer 16

var
Can be used inside and outside of functions
Variable declaration and value assignment can be done separately

:=
Can only be used inside functions
Variable declaration and value assignment cannot be done separately (must be done on same line)

Question 17

Multiple Variable Declaration

Answer 17

It is possible to declare multiple variables in same line.

Only possible to declare one type of variable per line

var a, b, c, d int = 1, 3, 5, 7

var (
a int
b int = 1
c string = “hello
)

If type keyword is not specified, different types of variables can be declared in the same line

Question 18

Go variable naming rules

Answer 18

Must start with a letter or _
Cannot start with digit
Can only contain alpha numeric and _
Names are case sensitive!!
No length limit
Cannot be Go keywords

Question 19

Camel Case

Answer 19

myVariableName = “John”

Question 20

Pascal Case

Answer 20

MyVariableName = “John”

Question 21

Snake Case

Answer 21

my_variable_name = “John”

Question 22

How is Boolean data type declared?

Answer 22

bool

Question 23

What value can bool values take?

Answer 23

True or false

(Defaults to false if not declared)

Question 24

What are Boolean values used for?

Answer 24

Mostly conditional testing

Question 25

What do Integer data types do?

Answer 25

Used to store a whole number without decimals

Question 26

What is a signed integer?

Answer 26

int

Can store both positive and negative values

Question 27

What is an unsigned integer?

Answer 27

unit

Can only store non negative values

Question 28

Types of signed integers

Answer 28

int 32 or 64 depends on system
int8 -128 to 127
int16 -32768 to 32767
int32 -2147483648 to 2147483647
int64 very large

Question 29

Types of unsigned integers

Answer 29

uint depends on system
uint8 0 to 255
uint16 0 to 65535
uint32 0 to 4294967295
uint64 Very large

Question 30

What is a float data type?

Answer 30

Used to store positive and negative numbers with decimal points

Default is float64

Question 31

Types of float data types

Answer 31

float32 32 bits -3.4e+38 to “+

float64 64 bits -1.7e+308 to “+

Question 32

What is string data type?

Answer 32

Used to store a sequence of characters (text).

Must be surrounded by double quotes “ “

Default if no value is “ “

Question 33

What is a constant?

Answer 33

Assigned with const; becomes read-only. Value must be assigned when declared.

Used when variable should have fixed value that cannot be changed.

Usually written in all UPPER for easy identification and differentiation from other variables

Question 34

Constant types

Answer 34

Types constants: declared with a defined type

Untyped constants: declared without a type

Question 35

Functions to output text

Answer 35

Print()
Println()
Printf()

Question 36

Print() Function

Answer 36

Prints its arguments with default formatting

Question 37

How to print arguments in new lines?

Answer 37

\n

var i, j string = “Hello”, “World”

fmt.Print(i, “\n”)
fmt.Print(j, “\n”)

Prints:
Hello
World

Also:

fmt.Print(i, “ “, j)
fmt.Print(i, “\n”, j)
Will default with spaces if type is not a string

Question 38

\n

Answer 38

Creates new line

Question 39

Println() Function

Answer 39

White space is added between arguments and a new line added at the end of the

Question 40

Printf() Function

Answer 40

Formats its argument based on the given formatting verb and then prints them

Ex of formatting verbs:
%v used to print value of argument
%T used to print type of argument

fmt.Print(“i has value: %v and type: %T\”, i, j)

Question 41

%v

Answer 41

Prints the value in the default format

Question 42

%#v

Answer 42

Prints the value in go-syntax format

Question 43

%T

Answer 43

Prints type of the value

Question 44

%%

Answer 44

Prints the % sign