go by example part 2

5-go-by-example/11-range.go

@@ -0,0 +1,38 @@
+package main
+
+import "fmt"
+
+// range iterates over elements in a variety of data structures
+func main() {
+
+	// use range to sum the numbers in a slice
+	nums := []int{2, 3, 4}
+	sum := 0
+	for _, num := range nums {
+		sum += num
+	}
+	fmt.Println("sum:", sum)
+
+	// range on arrays and slices provides both the index and value for each entry
+	for i, num := range nums {
+		if num == 3 {
+			fmt.Println("index:", i)
+		}
+	}
+
+	// range on map iterates over key/value pairs
+	kvs := map[string]string{"a": "apple", "b": "banana"}
+	for k, v := range kvs {
+		fmt.Printf("%s -> %s\n", k, v)
+	}
+
+	// range iterate over keys of a map
+	for k := range kvs {
+		fmt.Println("key:", k)
+	}
+
+	// range on strings iterates over Unicode code points
+	for i, c := range "go" {
+		fmt.Println(i, c)
+	}
+}