When the properties of an HTML element change, they can be captured through onpropertychange. For example, when the value attribute of the object is modified by the script of the page, onchange cannot capture it, but onpropertychange can.
The specific understanding is: onpropertychange can capture changes in property values in time, and onchange can only activate the event by performing certain operations with the mouse when the property value changes!
But onpropertychange is only supported by IE. How to solve it under FireFox? Firefox's event oninput has the same effect as IE's onproperchange.