init

go/notes.md

@@ -0,0 +1,126 @@
+---
+layout: default
+title: Golang notes
+categories: programming
+---
+
+```go
+ch := make(chan int)
+go func() {
+    ch <- 42
+}()
+fmt.Println(<-ch)
+```
+
+
+```go
+type Base struct {
+    ID int
+}
+
+type User struct {
+    Base
+    Name string
+}
+
+u := User{Base: Base{ID: 1}, Name: "John"}
+fmt.Println(u.ID, u.Name)
+```
+
+```go
+ch := make(chan int)
+go func() {
+    ch <- 42
+}()
+fmt.Println(<-ch)
+```
+
+Custom String Representations:
+	•	Implement the Stringer interface for custom string representations of your types
+
+```go
+type Person struct {
+    Name string
+    Age  int
+}
+
+func (p Person) String() string {
+    return fmt.Sprintf("%s is %d years old", p.Name, p.Age)
+}
+
+p := Person{Name: "Alice", Age: 30}
+fmt.Println(p)
+```
+
+Use init Function for Initialization:
+	•	The init function is called before the main function and is useful for setup tasks.
+
+  ```go
+
+  var config Config
+
+func init() {
+    config = loadConfig()
+}
+
+func main() {
+    fmt.Println(config)
+}
+```
+
+
+```go
+func add(a, b int) int {
+    return a + b
+}
+
+func TestAdd(t *testing.T) {
+    result := add(2, 3)
+    if result != 5 {
+        t.Errorf("expected 5, got %d", result)
+    }
+}
+```
+
+Use context for Cancellation and Timeouts:
+	•	Use the context package to handle cancellation and timeouts in concurrent operations.
+
+
+```go
+func doWork(ctx context.Context) {
+    select {
+    case <-time.After(2 * time.Second):
+        fmt.Println("Work done")
+    case <-ctx.Done():
+        fmt.Println("Canceled")
+    }
+}
+
+func main() {
+    ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+    defer cancel()
+    go doWork(ctx)
+    time.Sleep(2 * time.Second)
+}
+```
+
+
+```go
+type Weekday int
+
+const (
+    Sunday Weekday = iota
+    Monday
+    Tuesday
+    Wednesday
+    Thursday
+    Friday
+    Saturday
+)
+
+func (d Weekday) String() string {
+    return [...]string{"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}[d]
+}
+
+fmt.Println(Monday) // Output: Monday
+```