Now, once you know each of those, you can now do 25 more upper case letters and 25 more lower case letters then there are some other stuff like punctuation and things you see on the keyboard.

一旦你知道两者中的任何一个，你就知道了另外25个,大写字母和小写字母,标点和在键盘上的,各种符号也有ASCII码。

哈佛公开课 - 计算机科学课程节选