সি#

using System;
namespace MyApplication {
  class Program {
    static void Main(string[] args) {

    Dictionary<string, string> user = new() {
      {"নাম", "মোঃ আরিফ"},
      {"দেশ", "বাংলাদেশ"}
    };

    bool result = user.ContainsKey("নাম");

    Console.WriteLine(result);

    }
  }
}

using System;
namespace MyApplication {
  class Program {
    static void Main(string[] args) {

    Dictionary<string, string> user = new() {
      {"নাম", "মোঃ আরিফ"},
      {"দেশ", "বাংলাদেশ"}
    };

    bool result = user.ContainsValue("বাংলাদেশ");

    Console.WriteLine(result);

    }
  }
}

using System;
namespace MyApplication {
  class Program {
    static void Main(string[] args) {

    Dictionary<string, string> user = new() {
      {"নাম", "মোঃ আরিফ"},
      {"দেশ", "বাংলাদেশ"}
    };

    user.Add("শহর", "ঢাকা");

    Console.WriteLine(user.Count);

    }
  }
}

using System;
namespace MyApplication {
  class Program {
    static void Main(string[] args) {

    Dictionary<string, string> user = new() {
      {"নাম", "মোঃ আরিফ"},
      {"দেশ", "বাংলাদেশ"}
    };

    bool result = user.Remove("নাম");

    Console.WriteLine(result);

    }
  }
}

using System;
namespace MyApplication {
  class Program {
    static void Main(string[] args) {

    Dictionary<string, string> user = new() {
      {"নাম", "মোঃ আরিফ"},
      {"দেশ", "বাংলাদেশ"}
    };

    var result = user.Keys;

    foreach (var key in result) {
      Console.WriteLine(key);
    }

    }
  }
}

using System;
namespace MyApplication {
  class Program {
    static void Main(string[] args) {

    Dictionary<string, string> user = new() {
      {"নাম", "মোঃ আরিফ"},
      {"দেশ", "বাংলাদেশ"}
    };

    var result = user.Values;

    foreach (var value in result) {
      Console.WriteLine(value);
    }

    }
  }
}