using System;

public class Program

{

    public static void Main()

    {

        string str = "FooBar";

        MyObject obj = new MyObject {

            Str1 = str.Substring(0, 3),

            Str2 = str.Substring(3, 3),

            Str3 = str.Substring(6, 3),

            Str4 = str.Substring(9, 3)

        };

    }

}

​

public class MyObject {

    public string Str1 = "Foo";

    public string Str2 = "Foo";

    public string Str3 = "Foo";

    public string Str4 = "Foo";

}