Learn Go in 12 Minutes

Author: jakewright

go/01-learn-go/01-hello-world.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("Hello, World!")
+}

go/01-learn-go/02-variables.go

@@ -0,0 +1,11 @@
+package main
+
+import "fmt"
+
+func main() {
+	x := 5
+	y := 7
+	sum := x + y
+
+	fmt.Println(sum)
+}

go/01-learn-go/03-if.go

@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+func main() {
+	x := 5
+
+	if x > 6 {
+		fmt.Println("More than 6")
+	} else if x < 2 {
+		fmt.Println("Less than 2")
+	} else {
+		fmt.Println("Something else")
+	}
+}

go/01-learn-go/04-arrays.go

@@ -0,0 +1,25 @@
+package main
+
+import "fmt"
+
+func main() {
+	// An array has a length and a member type
+	var a [5]int
+	fmt.Println(a)
+
+	// Use square brackets to index an array
+	a[2] = 7
+	fmt.Println(a)
+
+	// Initialise an array with curly brackets
+	b := [5]int{5, 4, 3, 2, 1}
+	fmt.Println(b)
+
+	// Remove the element count to create a slice
+	s := []int{5, 4, 3, 2, 1}
+	fmt.Println(s)
+
+	// Use append to add something new to the array
+	s = append(s, 13)
+	fmt.Println(s)
+}

go/01-learn-go/05-maps.go

@@ -0,0 +1,18 @@
+package main
+
+import "fmt"
+
+func main() {
+	vertices := make(map[string]int)
+
+	vertices["triangle"] = 3
+	vertices["square"] = 4
+	vertices["dodecagon"] = 12
+
+	fmt.Println(vertices)
+	fmt.Println(vertices["triangle"])
+
+	delete(vertices, "square")
+
+	fmt.Println(vertices)
+}

go/01-learn-go/06-loops.go

@@ -0,0 +1,32 @@
+package main
+
+import "fmt"
+
+func main() {
+	// For loop
+	for i := 0; i < 5; i++ {
+		fmt.Println(i)
+	}
+
+	// While loop
+	i := 0
+	for i < 5 {
+		fmt.Println(i)
+		i++
+	}
+
+	// For each loop
+	arr := [3]string{"a", "b", "c"}
+
+	for index, value := range arr {
+		fmt.Println("index:", index, "value:", value)
+	}
+
+	m := make(map[string]string)
+	m["a"] = "alpha"
+	m["b"] = "beta"
+
+	for key, value := range m {
+		fmt.Println("key:", key, "value:", value)
+	}
+}

go/01-learn-go/07-functions.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"math"
+)
+
+func main() {
+	result := sum(2, 3)
+	fmt.Println(result)
+
+	result2, err := sqrt(16)
+	if err != nil {
+		fmt.Println(err)
+	} else {
+		fmt.Println(result2)
+	}
+}
+
+func sum(x, y int) int {
+	return x + y
+}
+
+func sqrt(x float64) (float64, error) {
+	if x < 0 {
+		return 0, errors.New("Undefined for negative numbers")
+	}
+
+	return math.Sqrt(x), nil
+}

go/01-learn-go/08-struct.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+type person struct {
+	name string
+	age  int
+}
+
+func main() {
+	p := person{name: "Jake", age: 23}
+	fmt.Println(p)
+	fmt.Println(p.age)
+}

go/01-learn-go/09-pointers.go

@@ -0,0 +1,22 @@
+package main
+
+import "fmt"
+
+func main() {
+	i := 7
+	fmt.Println("Memory address:", &i)
+
+	inc1(i)
+	fmt.Println("i not modified:", i)
+
+	inc2(&i)
+	fmt.Println("i incremented successfully:", i)
+}
+
+func inc1(x int) {
+	x++
+}
+
+func inc2(x *int) {
+	*x++
+}