How to refactor nested if else?

Question

C++ / C#

There is a class with a set of states. This class has N functions. Each function must do one thing or another depending on the current state, checking input along the way. In the end, each function looks like something like

private void FuncN(string[] params)
{
    if (CheckFuncNParams(params))
        if (state == State.StateX)
            if (collection.ContainsKey(params[2]))
                index++;
            else
                Console.WriteLine("error message 3");
        else
            Console.WriteLine("error message 2");
    else
       Console.WriteLine("error message 1");
}

You can expand the checks to linear ones, but I don’t know how much better this made it

private void FuncN(string[] params)
{
    if (!CheckFuncNParams(params))
    {
        Console.WriteLine("error message 1");
        return;
    }
    if (state != State.StateX)
    {
        Console.WriteLine("error message 2");
        return;
    }
    if (collection.ContainsKey(params[2]))
        index++;
    else
        Console.WriteLine("error message 3");
}

Answer 1

It is necessary to move everything into methods. And the text that is entered in Console.WriteLine is generated depending on the error