Initial commit - learning the basics

tour_of_go/l3/\

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"fmt"
+)
+
+func Sqrt(x float64) float64 {
+
+}
+
+func main() {
+	fmt.Println(Sqrt(2))
+}

tour_of_go/l3/conditionals.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+func pow(x, n, lim float64) float64 {
+	if v := math.Pow(x, n); v < lim {
+		return v
+	} else {
+		fmt.Printf("%g >= %g\n", v, lim)
+	}
+	return lim
+}
+
+func main() {
+	fmt.Println(
+		pow(3, 2, 10),
+		pow(3, 3, 20),
+	)
+}

tour_of_go/l3/ex1.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+)
+
+func Sqrt(x float64) float64 {
+	precision := 0.00001
+	old_z := 0.0
+	z := x
+	iter := 0
+	for (z - old_z) > precision {
+		iter += 1
+		old_z := z
+		z -= (z*z - x) / (2*z)
+		if old_z - z < 0 {
+			if ((old_z - z) * -1) < precision {
+				fmt.Println("Required precision has been reached after", iter, "iterations! Square root of", x , "is", z)
+				return z
+			}
+		} else if (old_z - z) < precision {
+			fmt.Println("Required precision has been reached after", iter, "iterations! Square root of", x , "is", z)
+			return z
+		}
+	}
+	return z
+}
+
+func main() {
+	fmt.Println(Sqrt(2))
+	fmt.Println(Sqrt(29))
+}

tour_of_go/l3/loops.go

@@ -0,0 +1,29 @@
+package main
+
+import ( 
+	"fmt"
+	"math"
+)
+
+func sqrt(x float64) string {
+	if x < 0 {
+		return sqrt(-x) + "i"
+	}
+	return fmt.Sprint(math.Sqrt(x))
+}
+
+func main() {
+	sum := 0
+	for i := 0; i < 10; i++ {
+		sum += 1
+	}
+	fmt.Println(sum)
+
+	sum_2 := 1
+	for sum_2 < 1000 {
+		sum_2 += sum_2
+	}
+	fmt.Println(sum_2)
+
+	fmt.Println(sqrt(2), sqrt(-4))
+}

tour_of_go/l3/switch.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"fmt"
+	"time"
+	"runtime"
+)
+
+func letsDefer(text string) {
+	defer fmt.Println(text)
+	fmt.Print("I have deferred: ")
+}
+
+func main() {
+	fmt.Print("Go runs on ")
+	switch os := runtime.GOOS; os {
+	case "darwin":
+		fmt.Println("macOS.")
+	case "linux":
+		fmt.Println("Linux.")
+	default:
+		fmt.Printf("%s.\n", os)
+	}
+
+	fmt.Println("When's Saturday?")
+	today := time.Now().Weekday()
+	switch time.Saturday {
+	case today + 0:
+		fmt.Println("Today.")
+	case today + 1:
+		fmt.Println("Tomorrow.")
+	case today + 2:
+		fmt.Println("In two days.")
+	default:
+		fmt.Println("Too far away.")
+	}
+
+	t := time.Now()
+	switch {
+	case t.Hour() < 12:
+		fmt.Println("Good morning!")
+	case t.Hour() < 17:
+		fmt.Println("Good afternoon")
+	default:
+		fmt.Println("Good evening.")
+	}
+
+	letsDefer("Some stuff")
+
+	fmt.Println("Counting...")
+	for i:=0; i<10; i++ {
+		defer fmt.Println(i)
+	}
+	fmt.Println("Done!")
+}