hello world with job example

master_concurrent_go/ch01/main.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+type Job struct {
+	i    int
+	max  int
+	text string
+}
+
+func outputText(j *Job) {
+	for j.i < j.max {
+		time.Sleep(1 * time.Millisecond)
+		fmt.Println(j.text)
+		j.i++
+	}
+}
+
+func main() {
+	hello := new(Job)
+	world := new(Job)
+	hello.text = "hello"
+	hello.i = 0
+	hello.max = 3
+	world.text = "world"
+	world.i = 0
+	world.max = 5
+	go outputText(hello)
+	outputText(world)
+}

the_go_programming_language/ch04/slice.go

@@ -12,3 +12,23 @@ func main() {
 	m2[0] = "Feb updated"
 	fmt.Print(m1, m2)
 }
+
+func appendInt(x []int, y int) []int {
+	var z []int
+	zlen := len(x) + 1
+	if zlen <= cap(x) {
+		// There is room to grow. Extend the slice.
+		z = x[:zlen]
+	} else {
+		// There is insufficient space. Allocate a new array.
+		// Grow by doubling, for amortized linear complexity.
+		zcap := zlen
+		if zcap < 2*len(x) {
+			zcap = 2 * len(x)
+		}
+		z = make([]int, zlen, zcap)
+		copy(z, x) // a built-in function; see text
+	}
+	z[len(x)] = y
+	return z
+}