# Exponent
> Return an integer corresponding to the unbiased exponent of a [double-precision floating-point number][ieee754].
## Usage
```javascript
var exponent = require( '@stdlib/number/float64/base/exponent' );
```
#### exponent( x )
Returns an `integer` corresponding to the unbiased exponent of a [double-precision floating-point number][ieee754].
```javascript
var exp = exponent( 3.14e307 ); // => 2**1021 ~ 1e307
// returns 1021
exp = exponent( 3.14e-307 ); // => 2**-1019 ~ 1e-307
// returns -1019
exp = exponent( -3.14 );
// returns 1
exp = exponent( 0.0 );
// returns -1023
exp = exponent( NaN );
// returns 1024
```
## Examples
```javascript
var randu = require( '@stdlib/random/base/randu' );
var round = require( '@stdlib/math/base/special/round' );
var pow = require( '@stdlib/math/base/special/pow' );
var exponent = require( '@stdlib/number/float64/base/exponent' );
var frac;
var exp;
var x;
var e;
var i;
// Generate random numbers and extract their exponents...
for ( i = 0; i < 100; i++ ) {
frac = randu() * 10.0;
exp = round( randu()*646.0 ) - 323;
x = frac * pow( 10.0, exp );
e = exponent( x );
console.log( 'x: %d. unbiased exponent: %d.', x, e );
}
```
[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985