# isComplex128
> Test if a value is a [128-bit complex number][@stdlib/complex/float64].
## Usage
```javascript
var isComplex128 = require( '@stdlib/assert/is-complex128' );
```
#### isComplex128( value )
Tests if a value is a [128-bit complex number][@stdlib/complex/float64].
```javascript
var Complex128 = require( '@stdlib/complex/float64' );
var x = new Complex128( 1.0, 3.0 );
var bool = isComplex128( x );
// returns true
```
## Examples
```javascript
var Complex64 = require( '@stdlib/complex/float32' );
var Complex128 = require( '@stdlib/complex/float64' );
var isComplex128 = require( '@stdlib/assert/is-complex128' );
var out = isComplex128( new Complex128( 3.0, 1.0 ) );
// returns true
out = isComplex128( new Complex64( 2.0, 2.0 ) );
// returns false
out = isComplex128( {} );
// returns false
out = isComplex128( null );
// returns false
```
[@stdlib/complex/float64]: https://www.npmjs.com/package/@stdlib/complex-float64