Well it turns out a bunch of years ago people just decided that if we have the ability to express numbers and we actually care about expressing letters of the alphabet, well we just need some kind of mapping between one and the other, ASCII and so thus was born what's generally called the ASCII.

结果证实，数年前,人们觉得如果我们,有数字表达能力,而我们真正在乎其实是字符的表达，那么我们就需要数字和字符的某种对应关系，于是就有了俗称的。

哈佛公开课 - 计算机科学课程节选