<!DOCTYPE html>
<html>
<head>
<title>vue-双向数据绑定的简单实现</title>
</head>
<body>
<input type="text" name="" id="inputText">
<span id='textSpan'></span>
<script type="text/javascript">
let obj = {},
inputText = document.querySelector('#inputText'),
textSpan = document.querySelector('#textSpan')
Object.defineProperty(obj, 'foo', {
set: function (newValue) {
inputText.value = newValue
textSpan.innerHTML = newValue
}
})
inputText.addEventListener('keyup', function (e) {
obj.foo = e.target.value
})
</script>
</body>
</html>