[GPWG]-Unit-0--Getting-started

2020-03-07

Unit 0 Getting started

lesson 1 get ready, get set, go

With the Go Playground you can start using Go without installing anything.
Every Go program is made up of functions contained in packages.
To print text on the screen, use the fmt package provided by the standard library.
Punctuation is just as important in programming languages as it is in natural languages.
You used 3 of the 25 Go keywords: package, import, and func

break        default      func         interface    select
case         defer        go           map          struct
chan         else         goto         package      switch
const        fallthrough  if           range        type
continue     for          import       return       var

Unit 1 Imperative programming

Travel to Mars.

lesson 2 a glorified calculator

package main

import "fmt"

func main() {
	fmt.Print("My weight on the surface of Mars is ")
	fmt.Print(149.0 * 0.3783) // always 37.83%
	fmt.Print(" lbs, and I would be ")
	fmt.Print(41 * 365 / 687)
	fmt.Print(" years old.")

	fmt.Println()
	fmt.Println("My weight on the surface of Mars is", 70*0.3783, " KG, and I would be ", 36*365/687, " years old.")

	//  %v for the value of the expression. https://golang.org/pkg/fmt/
	fmt.Printf("My weight on the surface of Mars is %v KG, and I would be %v  years old.\n", 70*0.3783, 36*365/687)

	//align text.
	// positive value pads with spaces to the left,
	// negtive number pads with spaces to the right.
	fmt.Printf("%-15v $%4v\n", "SpaceX", 94)
	fmt.Printf("%-15v $%4v\n", "Virgin Galactic", 100)

	const lightSpeed = 299792 // km/s
	var distance = 56000000   //km
	fmt.Println(distance/lightSpeed, " seconds")
	distance = 401000000
	fmt.Println(distance/lightSpeed, " seconds")
}