# isNegativeNumber
> Test if a value is a number having a negative value.
## Usage
```javascript
var isNegativeNumber = require( '@stdlib/assert/is-negative-number' );
```
#### isNegativeNumber( value )
Tests if a `value` is a `number` having a negative value.
```javascript
var Number = require( '@stdlib/number/ctor' );
var bool = isNegativeNumber( -5.0 );
// returns true
bool = isNegativeNumber( new Number( -5.0 ) );
// returns true
bool = isNegativeNumber( -3.14 );
// returns true
bool = isNegativeNumber( 5.0 );
// returns false
bool = isNegativeNumber( null );
// returns false
```
#### isNegativeNumber.isPrimitive( value )
Tests if a `value` is a primitive `number` having a negative value.
```javascript
var Number = require( '@stdlib/number/ctor' );
var bool = isNegativeNumber.isPrimitive( -3.0 );
// returns true
bool = isNegativeNumber.isPrimitive( new Number( -3.0 ) );
// returns false
```
#### isNegativeNumber.isObject( value )
Tests if a `value` is a `Number` object having a negative value.
```javascript
var Number = require( '@stdlib/number/ctor' );
var bool = isNegativeNumber.isObject( -3.0 );
// returns false
bool = isNegativeNumber.isObject( new Number( -3.0 ) );
// returns true
```
## Examples
```javascript
var Number = require( '@stdlib/number/ctor' );
var isNegativeNumber = require( '@stdlib/assert/is-negative-number' );
var bool = isNegativeNumber( -5.0 );
// returns true
bool = isNegativeNumber( new Number( -5.0 ) );
// returns true
bool = isNegativeNumber( -3.14 );
// returns true
bool = isNegativeNumber( 0.0 );
// returns false
bool = isNegativeNumber( 5.0 );
// returns false
bool = isNegativeNumber( '-5' );
// returns false
bool = isNegativeNumber( null );
// returns false
```