function compareDataViews(view1, view2) {
  if (view1.byteLength !== view2.byteLength) {
    return false;
  }
  const view1Array = new Uint8Array(view1.buffer);
  const view2Array = new Uint8Array(view2.buffer);
  for (let i = 0; i < view1Array.length; i++) {
    if (view1Array[i] !== view2Array[i]) {
      return false;
    }
  }
  return true;
}
 
const data1 = new Uint8Array([0x12, 0x34, 0x56, 0x78]).buffer;
const data2 = new Uint8Array([0x56, 0x78]).buffer;
 
const view1 = new DataView(data1, 0, 2);
const view2 = new DataView(data1, 2, 2);
const view3 = new DataView(data2);
 
console.log("view1 : " + view1.getUint16(0).toString(16));
console.log("view2 : " + view2.getUint16(0).toString(16));
console.log("view3 : " + view3.getUint16(0).toString(16));
console.log("view1 == view2 : " + compareDataViews(view1, view2));
console.log("view2 == view3 : " + compareDataViews(view2, view3));
console.log("view1 == view3 : " + compareDataViews(view1, view3));
 

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