# Alternative syntax (no colon): use alternate if set, otherwise empty
CACHE_ENABLED=${NODE_ENV+true}
```
```js
// index.js
console.log('NODE_ENV', process.env.NODE_ENV)
console.log('DEBUG_MODE', process.env.DEBUG_MODE)
console.log('LOG_LEVEL', process.env.LOG_LEVEL)
console.log('CACHE_ENABLED', process.env.CACHE_ENABLED)
```
```sh
$ dotenvx run --debug -- node index.js
[dotenvx@1.X.X] injecting env (4) from .env
NODE_ENV production
DEBUG_MODE false
LOG_LEVEL error
CACHE_ENABLED true
```

</details>
<details><summary>`run` - Interpolation Syntax Summary (Variable Expansion, Default/Alternate Values)</summary><br>

Complete reference for variable interpolation patterns supported by dotenvx:

```ini