javascript instance accessor property
DataView.prototype.byteOffset
The byteOffset accessor property of DataView instances returns the offset (in bytes) of this view from the start of its ArrayBuffer or SharedArrayBuffer.
Interactive exampleOpen the canonical MDN source to run this embedded demo.
// Create an ArrayBuffer with a size in bytes
const buffer = new ArrayBuffer(16);
const view = new DataView(buffer, 12, 4); // From byte 12 for the next 4 bytes
console.log(view.byteOffset);
// Expected output: 12
Description
The byteOffset 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 DataView is constructed and cannot be changed. However, the byteOffset becomes 0 if the underlying buffer is resized such that the viewed range is no longer valid.
Examples
Using the byteOffset property
const buffer = new ArrayBuffer(8);
const dataview = new DataView(buffer);
dataview.byteOffset; // 0 (no offset specified)
const dataview2 = new DataView(buffer, 3);
dataview2.byteOffset; // 3 (as specified when constructing the DataView)
const buffer2 = new ArrayBuffer(16, { maxByteLength: 32 });
const dataviewLengthTracking = new DataView(buffer2, 4);
dataviewLengthTracking.byteOffset; // 4
buffer2.resize(3);
dataviewLengthTracking.byteOffset; // 0 (viewed range is no longer valid)
Specifications
SpecificationsStandards references are available on the canonical MDN page.
Browser compatibility
Browser compatibilityCompatibility data is available on the canonical MDN page.