---
title: Defs.setIfUnset()
---

Sets the defs entry stored under _name_ to _value_, but only if it 
is not currently set to any value (if it is undefined).

## Signature

```js
Defs defs.setIfUnset(
  String name,
  String value
)
```

This object is chainable as it returns the `Defs` object.
