StackOverflow 文件 D Language 教程 關聯陣列 檢查是否存在金鑰 檢查是否存在金鑰 Created: November-22, 2018 int[string] numbers = ["a" : 10, "b" : 20]; assert("a" in numbers); assert("b" in numbers); assert("c" in numbers); 刪除鍵值對