# Euler's Number
> The mathematical constant [_e_][e].
## Usage
```javascript
var e = require( '@stdlib/constants/float64/e' );
```
#### e
The mathematical constant [_e_][e], also known as Euler's number or Napier's constant. [_e_][e] is the base of the natural logarithm.
```javascript
var bool = ( e === 2.718281828459045 );
// returns true
```
## Examples
```javascript
var e = require( '@stdlib/constants/float64/e' );
console.log( e );
// => 2.718281828459045
```
[e]: https://en.wikipedia.org/wiki/E_%28mathematical_constant%29