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c#data-structuresreflectionmergeanonymous-types

How to easily merge two anonymous objects with different data structure?

I would like to merge these two anonymous objects:

var man1 = new {
    name = new {
        first = "viet"
    },
    age = 20
};

var man2 = new {
    name = new {
        last = "vo"
    },
    address = "123 street"
};

Into a single one:

var man = new {
    name = new {
        first = "viet",
        last = "vo"
    },
    age = 20,
    address = "123 street"
};

I looked for a solution but found nothing clever.

Solution

  • There's nothing built-in in the C# language to support your use case. Thus, the question in your title needs to be answered with "Sorry, there is no easy way".

    I can offer the following alternatives:

    1. Do it manually:

      var man = new {
    name = new {
        first = man1.name.first,
        last = man2.name.first
    },
    age = man1.age,
    address = man2.address
};

    2. Use a class instead of an anonymous type for the resulting type (let's call it CompleteMan). Then, you can

      • create a new instance var man = new CompleteMan(); ,
      • use reflection to collect the properties and values from your "partial men" (man1 and man2),
      • assign those values to the properties of your man.

      It's "easy" in the sense that the implementation will be fairly straight-forward, but it will still be a lot of code, and you need to take your nested types (name) into account.

      If you desperately want to avoid non-anonymous types, you could probably use an empty anonymous target object, but creating this object (var man = new { name = new { first = (string)null, last = (string)null, ...) is not really less work than creating a class in the first place.

    3. Use a dedicated dynamic data structure instead of anonymous C# classes: