Chapter review

For review, the complete version of the Default.aspx.cs file for this chapter, including comments, is shown in the following code block:

using System;//needed for array, Convert, and Converter
delegate double CompareValues(double x, double y);//delegate for defining expression bodied lambda
public partial class _Default :System.Web.UI.Page
{
    double FromStringToDouble(string s) => Convert.ToDouble(s);//expression bodied function member
    protected void Button1_Click(object sender, EventArgs e)
    {
        //split entries into array of strings
        string[] vals = TextBox1.Text.Split(new char[] { ',' });
        //line 10 below converts all strings to doubles using the 
        //vals array, and a new Converter object
        //which really just calls FromStringToDouble
        double[] doubleVals = 
        Array.ConvertAll(vals, new Converter<string, double>(FromStringToDouble));
        //lines 13-17 define the expression bodied lambda, this one compares two 
        //values and returns the bigger
        CompareValues compareValues = (xin, yin) =>
        {
            double x = xin, y = yin;
            return x > y ? x : y;
        };
        //line 19 invokes CompareValuesInList, which needs the lambda, and 
        //list of values to compare
        sampLabel.Text = 
        CompareValuesInList(compareValues, doubleVals[0], doubleVals[1],doubleVals[2]).ToString();
    }
    //lines 22-25 below return either third value if it's biggest, 
    //or one of the other two
    static double CompareValuesInList(CompareValues compFirstTwo, double first, double second, double     third)
    {
        return third > compFirstTwo(first, second) ? third : compFirstTwo(first, second);
    }
}