Create Object from MenuItem

MyObjectCreateUtils.cs

        [MenuItem("GameObject/Foo", false, -1)]
        public static void CreateFoo(MenuCommand command = null)
        {
            // When called from MenuItem, this method is executed for every selected objects in the Hierarchy.
            if (command != null)
            {
                var context = command.context;
                if (context != null && context != Selection.activeObject) return;
            }
            var parents = Selection.transforms;
            foreach(var parent in parents)
            {
                Create(parent);
            }
            if (parents.Length == 0)
            {
                Create(null);
            }

            void Create(Transform parent)
            {
                // Create what you want here.
                var go = new GameObject("bar");
                go.transform.SetParent(parent, false);
            }
        }