You just need to come up with a convention that maps the numbers that are very easy for a computer to store.

你只需要提出一个使之与数字对应的协定,那样计算机就可以方便地存储它们。

哈佛公开课 - 计算机科学课程节选

But if we know that 65 is the int that maps to the capital letter "A," we've already seen verbally that you can convert letters to numbers and numbers to letters, and so here's the syntax with which we'll soon be doing that.

如果我们知道65是个整型数，对应的是,大写字母“A“，我们已经口头地说明,我们可以把数字转换为字符，字符转化为数字，所以这里就是我们将要学习的一种语法。

哈佛公开课 - 计算机科学课程节选