// Shows information about fmt package, Println function
godoc fmt Println

// Int
const pi float64 = 3.14159265
fmt.Printf("%f \n", pi) // Use newlines with Printf or it won't skip to the next line
fmt.Printf("%f.3f \n", pi) // to 3 decimal places
var (
  varA = 2
  varB = 3
)
fmt.Printf("%d \n", 100) //returns 100 because %d is int

// String
// can use " or `
var myName string = "Adam"
fmt.Println(len(myName)) // returns 4
fmt.Println(myName + " is a robot")

fmt.Println("I like \n \n ")
fmt.Println("new lines")

// Boolean
var isOver40 bool = false
fmt.Printf("%T \n", pi) // return float64 (%T shows the Type)
fmt.Printf("%t \n", pi) // returns false because %t is bool

fmt.Println("Hello World")
var age int = 33
var favNum float64 = 1.6180339
randNum := 1
fmt.Println(age, " ", favNum)
fmt.Println(age, favNum)

num1 := 1000
num2 := 337
fmt.Println(num1 + num2)

fmt.Println("true && false =", true && false)
fmt.Println("true || false =", true || false)
fmt.Println("!true", !true)

i := 1
for i <= 10 {
  fmt.Println(i)
  i++
}

for j := 0; j < 5; j++ {
  fmt.Println(j)
}

yourAge := 18
if yourAge >= 16 {
  fmt.Println("You can drive")
} else {
  fmt.Printlb("You can't drive!")
}

// Go exits when the first condition is true
// In this example, the `else if` is not evaluated
yourAge := 18
if yourAge >= 16 {
  fmt.Println("You can drive")
} else if yourAge >= 18 {
  fmt.Println("You can vote")
} else {
  fmt.Println("You can have fun")
}

yourAge := 5
switch yourAge {
  case 16: fmt.Println("Go drive")
  case 18: fmt.Println("Go vote")
  default: fmt.Println("Go have fun")
}

var favNums2[5] float64
favNums2[0] = 163
favnums2[1] = 78557
favnums2[2] = 691
favnums2[3] = 3.141
favnums2[4] = 1.618

fmt.Println(favNums2[3])

favNums3 := [5]float64 {1, 2, 3, 4, 5}
for i, value := range favNums3 {
  fmt.Println(value, i)
}

// Index positions hidden
favNums3 := [5]float64 {1, 2, 3, 4, 5}
for _, value := range favNums3 {
  fmt.Println(value)
}

numSlice := []int {5, 4, 3, 2, 1}
numSlice2 := numSlice[3:5]
fmt.Println("numSlice2[0] =", numSlice2[0]) // returns 2

// Implicit start from zero
fmt.Println("numSlice2[:2] =", numSlice2[:2]) // returns [2 1]

// Implicit return all
fmt.Println("numSlice2[0:] =", numSlice2[0:])