html - 为什么类型为 "number"的 html 输入允许在字段中输入字母 'e'？

Question

我有以下 html5 输入元素:

<input type="number">

为什么这个输入允许在输入字段中输入字符“e”？无法输入其他字母字符(如预期的那样)

使用 chrome v. 44.0.2403.107

下面的例子来看看我的意思。

<input type="number">

Answer 1

因为这正是 the spec说它应该工作。输入的数字可以接受floating-point numbers ，包括负号和 e 或 E 字符(其中指数是 e 或 E 之后的数字):

A floating-point number consists of the following parts, in exactly the following order:

1. Optionally, the first character may be a "-" character.
2. One or more characters in the range "0—9".
3. Optionally, the following parts, in exactly the following order:
   1. a "." character
   2. one or more characters in the range "0—9"
4. Optionally, the following parts, in exactly the following order:
   1. a "e" character or "E" character
   2. optionally, a "-" character or "+" character
   3. One or more characters in the range "0—9".