# isFunction
> Test if a value is a function.
## Usage
```javascript
var isFunction = require( '@stdlib/assert/is-function' );
```
#### isFunction( value )
Tests if a `value` is a `function`.
```javascript
function beep() {
console.log( 'beep' );
}
var bool = isFunction( beep );
// returns true
```
## Examples
```javascript
var isFunction = require( '@stdlib/assert/is-function' );
var bool = isFunction( function foo() {} );
// returns true
bool = isFunction( 'beep' );
// returns false
bool = isFunction( 5 );
// returns false
bool = isFunction( true );
// returns false
bool = isFunction( null );
// returns false
bool = isFunction( [] );
// returns false
bool = isFunction( {} );
// returns false
```