DataView.prototype.byteLength

// Create an ArrayBuffer with a size in bytes const buffer = new ArrayBuffer(16); const view1 = new DataView(buffer); const view2 = new DataView(buffer, 12, 4); // From byte 12 for the next 4 bytes console.log(view1.byteLength + view2.byteLength); // 16 + 4 // Expected output: 20

const buffer = new ArrayBuffer(8); const dataview = new DataView(buffer); dataview.byteLength; // 8 (matches the byteLength of the buffer) const dataview2 = new DataView(buffer, 1, 5); dataview2.byteLength; // 5 (as specified when constructing the DataView) const dataview3 = new DataView(buffer, 2); dataview3.byteLength; // 6 (due to the offset of the constructed DataView) const buffer2 = new ArrayBuffer(16, { maxByteLength: 32 }); const dataviewLengthTracking = new DataView(buffer2, 4); dataviewLengthTracking.byteLength; // 12 (16 - 4) buffer2.resize(20); dataviewLengthTracking.byteLength; // 16 (20 - 4) buffer2.resize(3); dataviewLengthTracking.byteLength; // 0 (viewed range is no longer valid)