事件

 <button id="gos">点击</button>
<input type="text" placeholder="请输入用户名" id="btn">
<input type="text" placeholder="请输入密码" id="ptn">
<button>登录</button>
<script>

1.双击事件

    var $gos = document.getElementById('gos')
    $gos.ondblclick = (event) => {
        alert('请输入用户')
    }

2.键盘事件

    var $btn = document.getElementById('btn')
    $btn.onkeydown = (event) => {
        console.log(event)
    }

3.按下事件

    var $ptn = document.getElementById('ptn')
    $ptn.onkeypress = (event) => {
        console.log(event)
        if (event.charCode === 13) {
            alert('正在登录')
        }
    }

绑定事件和点击元素

    var $yeye = document.getElementById('yeye')
    $yeye.onclick = (event) => {
        alert('我是你爷爷', event.currentTarget)
        alert('我是你爷爷', event.target)
    }

输入框事件

     var $pin = document.getElementById('pin')
    $pin.oninput = (event) => {
        console.log(event)
    }