Variadic Interface Functions

Author: BenderScript

variadic_functions/main.go

@@ -0,0 +1,48 @@
+package main
+
+import "fmt"
+
+// Unpack operator breaks a slice into individual components. it ends with ... like slice...
+// Pack operator combine individual elements like integers into a slice. It starts with ... like ...Type
+// Effective Go talks about append but wish it would spend just a bit more time on the subject.
+
+var exNum int
+
+func main() {
+
+	variadicA([]string{"a", "b", "c"}...)
+	variadicA("d", "e", "f")
+
+	// The mythical variadic interface{}
+	variadicInterface(1.0, "a", 2, []int{1, 2})
+
+}
+
+func variadicA(elems ...string) {
+	exNum++
+	fmt.Printf("Example number: %d", exNum)
+	str := ""
+	for _, e := range elems {
+		str += e
+	}
+	fmt.Println("Output: ", str)
+}
+
+func variadicInterface(elems ...interface{}) {
+	exNum++
+	fmt.Printf("Example number: %d", exNum)
+	for _, e := range elems {
+		switch e.(type) {
+		case float64:
+			fmt.Println("Type is float64")
+		case int:
+			fmt.Println("Type is Integer")
+		case string:
+			fmt.Println("Type is String")
+		case []int:
+			fmt.Println("Type is []int")
+		default:
+			fmt.Printf("Catch-all. Type is %T", e)
+		}
+	}
+}