The byteLength accessor property of ArrayBuffer instances returns the length (in bytes) of this array buffer.
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 the array is constructed and cannot be changed. This property returns 0 if this ArrayBuffer has been detached.
Examples
Using byteLength
const buffer = new ArrayBuffer(8);
buffer.byteLength; // 8