C# syntax to initialize custom class/objects through constructor params in array?

Try adding square brackets after new MyClass and a semi-colon at the end

    MyClass[] testobjlist = new MyClass[] 
        {
         new MyClass(1001,1234,"Text 1", "abcdefghijklm", "ding"),
         new MyClass(1002,2345,"Text xx", "bla bla", "dong"),
         new MyClass(1003,8653,"Text yy", "blah blah even more", "bamm!")
        };

this will also work without a need to create a constructure

new MyClass [] { new MyClass { Field1 = "aa", Field2 = 1 } } 

Shorthand for the win:

var myClassList = new[]
{
    new MyClass(1001,1234,"Text 1", "abcdefghijklm", "ding"),
    new MyClass(1002,2345,"Text xx", "bla bla", "dong")
};