# isCircular
> Test if an object-like value contains a circular reference.
## Usage
```javascript
var isCircular = require( '@stdlib/assert/is-circular' );
```
#### isCircular( value )
Test if an object-like `value` contains a circular reference.
```javascript
var obj = {
'beep': 'boop'
};
var bool = isCircular( obj );
// returns false
obj.self = obj;
bool = isCircular( obj );
// returns true
```
## Notes
- Object-like values include `objects` (except for `null`), `arrays`, `functions`, regular expressions, `Date` objects, and any other JavaScript object to which properties may be bound.
## Examples
```javascript
var isCircular = require( '@stdlib/assert/is-circular' );
var obj1 = {
'a': 'beep',
'b': {
'c': 'boop'
}
};
obj1.b.self = obj1;
var bool = isCircular( obj1 );
// returns true
var obj2 = {
'a': {},
'b': obj1
};
bool = isCircular( obj2 );
// returns true
var arr = [ 1, 2, 3 ];
arr.push( arr );
bool = isCircular( arr );
// returns true
function circ() {}
circ.self = circ;
bool = isCircular( circ );
// returns true
var obj3 = {
'beep': 'boop'
};
bool = isCircular({
'a': obj3,
'b': obj3
});
// returns false
bool = isCircular( {} );
// returns false
bool = isCircular( null );
// returns false
```