5/12/26
A little surprising behavior I ran into today.
If you have an HTML input of type number:
<input type="number" />
Then you can enter a single e character as a totally valid value.
This is because you can use e as part of scientific notation so 2e2 is an actually valid number. In order to partially type that value, the number input allows the e char.
If you actually try to parse just e you get an invalid number.
I needed to add some additional Number.isNumber() around my input value to prevent this from being a valid value saved in the form.