Author: nonthasart

Diff for: arrays/main.go

@@ -0,0 +1,25 @@
+package main
+
+import "fmt"
+
+func main() {
+	var a [5]int
+	fmt.Println("emp:", a)
+
+	a[4] = 100
+	fmt.Println("set: ", a)
+	fmt.Println("get: ", a[4])
+
+	fmt.Println("len: ", len(a))
+
+	b := [5]int{1, 2, 3, 4, 5}
+	fmt.Println("dcl: ", b)
+
+	var twoD [2][3]int
+	for i := 0; i < 2; i++ {
+		for j := 0; j < 3; j++ {
+			twoD[i][j] = i + j
+		}
+	}
+	fmt.Println("2d: ", twoD)
+}

Diff for: constants/main.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+const s string = "constant"
+
+func main() {
+	fmt.Println(s)
+
+	const n = 500000000
+
+	const d = 3e20 / n
+	fmt.Println(d)
+
+	fmt.Println(int64(d))
+
+	fmt.Println(math.Sin(n))
+}

Diff for: for/main.go

@@ -0,0 +1,27 @@
+package main
+
+import "fmt"
+
+func main() {
+	i := 1
+	for i <= 3 {
+		fmt.Println(i)
+		i = i + 1
+	}
+
+	for j := 7; j <= 9; j++ {
+		fmt.Println(j)
+	}
+
+	for {
+		fmt.Println("loop")
+		break
+	}
+
+	for n := 0; n <= 5; n++ {
+		if n%2 == 0 {
+			continue
+		}
+		fmt.Println(n)
+	}
+}

Diff for: go.mod

@@ -0,0 +1,3 @@
+module github.com/nonthasart/gobyexample
+
+go 1.21.5

Diff for: hello-world/main.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("hello world")
+}

Diff for: if-else/main.go

@@ -0,0 +1,27 @@
+package main
+
+import "fmt"
+
+func main() {
+	if 7%2 == 0 {
+		fmt.Println("7 is even")
+	} else {
+		fmt.Println("7 is odd")
+	}
+
+	if 8%4 == 0 {
+		fmt.Println("8 is divisible by 4")
+	}
+
+	if 7%2 == 0 || 8%2 == 0 {
+		fmt.Println("either 8 or 7 is even")
+	}
+
+	if num := 9; num <= 0 {
+		fmt.Println(num, "is negative")
+	} else if num < 10 {
+		fmt.Println(num, "has 1 digit")
+	} else {
+		fmt.Println(num, "has multiple digits")
+	}
+}

Diff for: maps/main.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"fmt"
+	"maps"
+)
+
+func main() {
+	m := make(map[string]int)
+
+	m["k1"] = 7
+	m["k2"] = 13
+
+	fmt.Println("map:", m)
+
+	v1 := m["k1"]
+	fmt.Println("v1:", v1)
+
+	v3 := m["k3"]
+	fmt.Println("v3:", v3)
+
+	fmt.Println("len:", len(m))
+
+	delete(m, "k2")
+	fmt.Println("map:", m)
+
+	clear(m)
+	fmt.Println("map:", m)
+
+	_, prs := m["k2"]
+	fmt.Println("prs", prs)
+
+	n := map[string]int{"foo": 1, "bar": 2}
+	fmt.Println("map:", n)
+
+	n2 := map[string]int{"foo": 1, "bar": 2}
+	if maps.Equal(n, n2) {
+		fmt.Println("n == n2")
+	}
+}

Diff for: range/main.go

@@ -0,0 +1,31 @@
+package main
+
+import "fmt"
+
+func main() {
+	nums := []int{2, 3, 4}
+	sum := 0
+	for _, num := range nums {
+		sum += num
+	}
+	fmt.Println("sum:", sum)
+
+	for i, num := range nums {
+		if num == 3 {
+			fmt.Println("index:", i)
+		}
+	}
+
+	kvs := map[string]string{"a": "apple", "b": "banana"}
+	for k, v := range kvs {
+		fmt.Printf("%s -> %s\n", k, v)
+	}
+
+	for k := range kvs {
+		fmt.Println("key:", k)
+	}
+
+	for i, c := range "go" {
+		fmt.Println(i, c)
+	}
+}

Diff for: slices/main.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"fmt"
+	"slices"
+)
+
+func main() {
+	var s []string
+	fmt.Println("uninit:", s, s == nil, len(s) == 0)
+
+	s = make([]string, 3)
+	fmt.Println("emp:", s, "len:", len(s), "cap:", cap(s))
+
+	s[0] = "a"
+	s[1] = "b"
+	s[2] = "c"
+	fmt.Println("set:", s)
+	fmt.Println("get:", s[2])
+
+	fmt.Println("len:", len(s))
+
+	s = append(s, "d")
+	s = append(s, "e", "f")
+	fmt.Println("apd:", s)
+
+	c := make([]string, len(s))
+	copy(c, s)
+	fmt.Println("cpy:", c)
+
+	l := s[2:5]
+	fmt.Println("sl1:", l)
+
+	l = s[:5]
+	fmt.Println("sl2:", l)
+
+	l = s[2:]
+	fmt.Println("sl3:", l)
+
+	t := []string{"g", "h", "i"}
+	fmt.Println("dcl:", t)
+
+	t2 := []string{"g", "h", "i"}
+	if slices.Equal(t, t2) {
+		fmt.Println("t == t2")
+	}
+
+	twoD := make([][]int, 3)
+	for i := 0; i < 3; i++ {
+		innerLen := i + 1
+		twoD[i] = make([]int, innerLen)
+		for j := 0; j < innerLen; j++ {
+			twoD[i][j] = i + j
+		}
+	}
+	fmt.Println("2d:", twoD)
+}

Diff for: switch/main.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func main() {
+	i := 2
+	fmt.Print("Write ", i, " as ")
+	switch i {
+	case 1:
+		fmt.Println("one")
+	case 2:
+		fmt.Println("two")
+	case 3:
+		fmt.Println("three")
+	}
+
+	switch time.Now().Weekday() {
+	case time.Saturday, time.Sunday:
+		fmt.Println("It's the weekend")
+	default:
+		fmt.Println("It's a weekday")
+	}
+
+	t := time.Now()
+	switch {
+	case t.Hour() < 12:
+		fmt.Println("It's before noon")
+	default:
+		fmt.Println("It's after noon")
+	}
+
+	whatAmI := func(i interface{}) {
+		switch t := i.(type) {
+		case bool:
+			fmt.Println("I'm a bool")
+		case int:
+			fmt.Println("I'm an int")
+		default:
+			fmt.Printf("Don't know type %T\n", t)
+		}
+	}
+	whatAmI(true)
+	whatAmI(1)
+	whatAmI("hey")
+}

Diff for: values/main.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("go" + "lang")
+
+	fmt.Println("1+1 =", 1+1)
+	fmt.Println("7.0/3.0 =", 7.0/3.0)
+
+	fmt.Println(true && false)
+	fmt.Println(true || false)
+	fmt.Println(!true)
+}

Diff for: variables/main.go

@@ -0,0 +1,20 @@
+package main
+
+import "fmt"
+
+func main() {
+	var a = "initial"
+	fmt.Println(a)
+
+	var b, c int = 1, 2
+	fmt.Println(b, c)
+
+	var d = true
+	fmt.Println(d)
+
+	var e int
+	fmt.Println(e)
+
+	f := "apple"
+	fmt.Println(f)
+}