html
<!DOCTYPE html>
<html>
<body>
<div id="app">
<input type="text" id="txt">
<p id="show"></p>
</div>
<script type="text/javascript">
var obj = {}
Object.defineProperty(obj, 'txt', {
// get: function () {
// return obj
// },
set: function (newValue) {
document.getElementById('txt').value = newValue
document.getElementById('show').innerHTML = newValue
}
})
document.getElementById('txt').addEventListener('keyup', function (e) {
obj.txt = e.target.value
})
</script>
</body>
</html>DevTools中随便输入 obj.txt = '12321z@2'，页面两处会相应的发生变化。