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# Reflect.preventExtensions()

The static **`Reflect.preventExtensions()`** method prevents new properties from ever being added to an object (i.e., prevents future extensions to the object). It is similar to [`Object.preventExtensions()`](../../globals/Object/preventExtensions.mdx), but with [some differences](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/preventExtensions#difference_with_object.preventextensions).

## Syntax

```js
Reflect.preventExtensions(target)
```

### Parameters

- `target`
  - : The target object on which to prevent extensions.

### Return value

A `Boolean` indicating whether or not the target was successfully set to prevent extensions.

### Exceptions

A [`TypeError`](../../globals/TypeError/TypeError.mdx), if `target` is not an `Object`.
