Merge pull request #96 from devlights/issue-#44-map-delete

Add map delete example ( close #44 )

Author: devlights

basic/map_/map_delete.go

@@ -0,0 +1,35 @@
+package map_
+
+import "fmt"
+
+func MapDelete() error {
+
+	var (
+		f = func(v map[string]int) {
+			fmt.Printf("len: %d\tval: %v\n", len(v), v)
+		}
+
+		m = map[string]int{
+			"a": 100,
+			"b": 200,
+		}
+	)
+
+	f(m)
+
+	// map から要素を削除する場合 組み込み関数 delete() を使う
+	delete(m, "a")
+
+	f(m)
+
+	delete(m, "b")
+
+	f(m)
+
+	// 存在しない要素を delete に渡してもエラーにはならない。何も起きないだけ。
+	delete(m, "a")
+
+	f(m)
+
+	return nil
+}

lib/mapping.go

@@ -44,6 +44,7 @@ func (m SampleMapping) MakeMapping() {
 	m["map_basic"] = map_.MapBasic
 	m["map_for"] = map_.MapFor
 	m["map_initialize"] = map_.MapInitialize
+	m["map_delete"] = map_.MapDelete
 	m["scope01"] = scope.Scope01
 	m["async01"] = async.Async01
 	m["reflection01"] = reflection.Reflection01