This document outlines an agenda for a workshop on learning Go from basic "Hello World" programs to building web services. The agenda covers Go basics like syntax, types, functions, arrays and slices, structs and interfaces. It also covers more advanced topics like concurrency with goroutines, channels and wait groups. Finally, it discusses building web services using the net/http package and interacting with databases using the database/sql package. Exercises are provided throughout for hands-on learning.

1. Learning Go From Hello
World to Web Service
Eric Potter
Sweetwater

2. Learning Go From Hello
World to Web Service
Eric Potter
Sweetwater

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4. Learning Go From Hello
World to Web Service
Eric Potter
Sweetwater

5. Agenda
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1:00 Intro, Background, Tooling, Basic Syntax
1:30 Exercises
2:00 Arrays / Slices, Types / Interfaces
2:30 Exercises
3:00 Go Routines
3:30 Exercises
4:00 Web Services
4:30 Exercises

6. Background
Before we go
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7. Creators
Rob Pike
• Worked at Bell
Labs and Google
• co-creator of
UTF-8
Ken Thompson
• Designed and
implemented the
original Unix
Robert Griesemer
• Worked on
Google's V8
JavaScript engine
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8. Fast
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10. Tools
All systems go
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11. Installation
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12. Go CLI
• go run
• go build
• go mod init
• go test
• go get
• go fmt
• etc
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13. IDEs
VS Code GoLand ($)
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14. Hello World
Demo
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15. Hello World
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16. Imports
Single Multiple
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17. Types
Go your own way
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18. Basic Types
• bool
• string
• int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64
• rune // alias for int32 that represents a Unicode code point
• float32, float64
• complex64, complex128
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19. Variable Declaration
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20. Syntax
Let it go
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21. Terse
; ( )
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22. Notable Omissions
++i
do {}
while
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23. Function Syntax
C#
public <returnType> <name> (<args>)
Go
func <name> (<args>) <returnType>
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24. Fizz Buzz
Demo
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25. Fizz Buzz
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26. Questions
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27. Exercise 1
Euler 1
1) If we list all the natural numbers below 10 that are multiples of 3
or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.
Find the sum of all the multiples of 3 or 5 below 1000.
2) The Sine value for 2 is positive and the value for 5 is negative.
Print the sum of the positive sine values from the input between 0
and 10. (hint import “math” and use math.Sin)
If you get done, try Euler 2 (https://projecteuler.net/problem=2)
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28. Euler 1
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30. Arrays
Go home
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31. Declaring Arrays
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32. Accessing Array Elements
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34. Iterate over an Array
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35. The size is part of the type
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36. Slices
Go home
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38. Dynamic Sizing
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39. Ranges
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40. Classes
Go home
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41. Classes
Go home
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Packages & Structs

42. Defining a Struct
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45. Associating Functions with Structs
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46. Interfaces
Go home
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47. Defining an Interface
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48. Checkerboard demo
Demo
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49. Questions
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50. Exercise 2
Create a GIF
Clone this repo: https://github.com/pottereric/GoGifBuilder
Using the image/gif and image/color packages, create a gif of a
checker board.
Using the same libraries, create an animated gif of a sine wave.
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51. Concurrency
You go your way,
I’ll go mine
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52. Concurrent Functions
Demo
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54. Channels
Go change the
channel
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55. TextEntryWithTimeout
Demo
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56. TextEntryWithTimeout
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57. WaitGroups
Go wait in the corner
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59. Questions
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60. Exercise 3
Create a GIF Concurrently
Modify your code that creates a sine wave gif to create the file
concurrently while the user enters the output file name.
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63. Web Services
Go on
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64. net/http Package
• The core functionality is in a standard library.
• There are packages like gin that provide structure.
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65. net/http
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66. net/http
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67. Data Access
Go get it
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68. database/sql
• Go uses a driver and plugin model.
• There are larger frameworks like Gorm
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69. database/sql
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70. Questions
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71. Exercise 4
Web Services
Create a webservice that returns the sine of a given number.
Create a webservice that returns your sine wave GIF
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72. Thank you
Eric Potter • @pottereric •
HumbleToolsmith.com
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