The setInt8() method of DataView instances takes a number and stores it as an 8-bit signed integer in the byte at the specified byte offset of this DataView.
// Create an ArrayBuffer with a size in bytes
const buffer = new ArrayBuffer(16);
const view = new DataView(buffer);
view.setInt8(1, 127); // Max signed 8-bit integer
console.log(view.getInt8(1));
// Expected output: 127setInt8(byteOffset, value)byteOffsetThe offset, in bytes, from the start of the view to store the data in.
valueThe value to set. For how the value is encoded in bytes, see Value encoding and normalization.
RangeErrorThrown if the byteOffset is set such that it would store beyond the end of the view.
const buffer = new ArrayBuffer(10);
const dataview = new DataView(buffer);
dataview.setInt8(0, 3);
dataview.getInt8(0); // 3