Type is set to number, yet somehow e is still allowed? Is it because e is 2.71 blah blah, and it’s considerred a number?

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‘**e**’ is the base of the Natural Logarithms, also known as Napier’s constant (invented by John Napier).

The number ‘**e**’ is a famous irrational number, and is one of the most important numbers in mathematics.

In this input type attribute,

```
<input type="number" />
```

You can set restrictions on what numbers that are accepted by using one or more of this rules:

- max - to chose the maximum value allowed
- min - to chose the minimum value allowed
- step - to chose the legal number intervals

And since ‘**e**’ is approximately equal to 2.71828. You can set rules to bypass it. But the user can still enter ‘**e**’ in the field because it is still considered a number.

for example:

```
<form action="#">
<label for="num-1">Number:</label>
<input type="number" name="num-1" step="10" />
<input type="submit" />
</form>
```

In this code, you can add the number ‘**e**’ here, but It will not be validated because the restrictions.

You can read more about the *Euler’s number* here in Wikipedia

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