c#基础补充

• params修饰符
• checked
• 扩展方法

params修饰符

static double CalculateAverage(params double[] values)
{
    double sum = 0;
    if (values.Length == 0)
        return sum;
    for (int i = 0; i < values.Length; i++)
    {
        sum+=values[i];
    }
    return sum / values.Length;
}
// params，传入 逗号 分隔的列表
AddLogLine(CalculateAverage(1.0, 3.0).ToString());
double[] data = { 1.0, 5.0 };
AddLogLine(CalculateAverage(data).ToString());

checked

static int Add(int a,int b)
{
    return a+b;
}
// 溢出
try
{
    checked
    {
        byte sum = (byte)Add(100, 200);
    }
}
catch (OverflowException ex)
{
    // Arithmetic operation resulted in an overflow.
    AddLogLine(ex.ToString());
}

扩展方法

static class Extentions2
{
    public static int ReverseDigits(this int i)
    {
        char[] digits = i.ToString().ToCharArray();
        Array.Reverse(digits);
        return int.Parse(new String(digits));
    }
}
// 扩展方法
AddLogLine(1234.ReverseDigits().ToString());