深入Vue实现原理

跟着大佬撸原理

https://www.jianshu.com/p/123146abdd1a

自己总结:

<div>
    <input type="text" id="input-msg">
    <p id="output-msg"></p>
</div>

<script>
    var inputMsg = document.getElementById('input-msg');
    var outputMsg = document.getElementById('output-msg');
    var obj = {
        msg: 'hello'
    };

    var key = 'msg';
    
    var val = obj[key];

    Object.defineProperty(obj, 'value', {
        enumerable: true,
        configurable: true,
        set: function (newValue) {
            val = newValue;
            outputMsg.innerHTML = val;
            console.log('setter',val);
            console.log('setter',obj);
        },

        get: function () {
            console.log('getter',val);
            return val;
        }
    })
    inputMsg.addEventListener('input',function(e){
        obj['value'] = e.target.value;
        console.log(e.target.value)
    })
    console.log(obj)
</script>

上面的Object.defineProperty监听obj的value，当在控制台打印obj.value的时候会走到get方法里面,当给obj.value = 2的时候，会走到set方法里面;