Why does modulus (%) operator work for char but not for floating types?

为什么模量（%）操作字符而不是浮点类型？

youdao

After each extinction, a rich variety of ammonoid species and body plans was replaced by a few free-floating types.

在每次物种灭绝之中，大量的菊石和体平面为少量浮游动物所替代。

youdao

It then calls the friend function spacefriend and passes the class object address as its argument, and calls the template function, beginning with integer types and then floating data types.

然后，调用友元函数spacefriend并将类对象的地址作为其参数传递。然后调用template函数，先使用整数类型，然后使用浮点数据类型。

youdao

All right. I want to return to some non-scalar types. So we've been looking, the last couple of lectures, at floating pointing numbers and integers.

好，我们现在回到一些,非基本类型的话题来，我们在过去的几节课里,一直在研究浮点数类型和integer类型。

麻省理工公开课 - 计算机科学及编程导论课程节选