Beginning C# 7 Hands-On - The Core Language

Outputting the results of the Summarize method

In the next stage, we'll make use of our Summarize method. So, type the following:

Label1.Text = $"Sum of values={Summarize(vals)}";

Here, within the curly braces, we place a call to Summarize and type (vals), which is of course the array you're passing in, and then type out.

Now we need one more thing. Right now, if you leave this line ending with just (vals), you will get an error. When you hover your mouse over Summarize, the tooltip popup says, There's no argument given that corresponds to the required formal parameter 'average' of '_Default.Summarize(double[],out double)'. In other words, you're missing this bit (out double average): the average value, the out parameter that is needed. To ...