C# Linq 類似Scala中的map的函數

Select可實現類似map的功能

> var arr = new byte[] { 2, 3, 4 };
> arr.Select(a => Convert.ToString(a, 16).PadLeft(2, '0'));
> var hex = arr.Select(a => Convert.ToString(a, 16).PadLeft(2, '0'));
> string.Join(" ",  hex)
"02 03 04"