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# DataView.prototype.byteLength

The **`byteLength`** accessor property represents the length (in bytes) of the dataview.

## Description

The `byteLength` property is an accessor property whose set accessor function is `undefined`, meaning that you can only read this property. The value is established when an `DataView` is constructed and cannot be changed. If the `DataView` is not specifying an offset or a `byteLength`, the `byteLength` of the referenced `ArrayBuffer` or `SharedArrayBuffer` will be returned.
