class对象
className
修改样式
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title><style>div {width: 200px;height: 200px;background-color: aqua;}.action {width: 300px;height: 300px;background-color: pnik;margin-left: 100px;}</style>
</head>
<body><div></div><script>let box = document.querySelector('div')box.className = 'action'</script>
</body>
</html>
classList
修改样式
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title><style>div {width: 200px;height: 200px;background-color: aqua;}.action {width: 300px;height: 300px;background-color: pnik;margin-left: 100px;}</style>
</head>
<body><div class="one"></div><script>let box = document.querySelector('div')// add 追加box.classList.add('action')// remove 移除box.classList.remove('one')// 切换类box.classList.toggle('one')</script>
</body>
</html>
修改表单属性
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><input type="text" name="" id="" value="请输入"><button disabled>按钮</button><input type="checkbox" name="" id="" class="agree"><script>let input = document.querySelector('input')input.value = '小米'input.type = 'password'let btn =document.querySelector('button')btn.disabled = truelet checkbox = document.querySelector('.agree')checkbox.checked = true</script>
</body>
</html>
间歇函数（定时器）
setInterval(function(){console.log('color');},1000)function show (){console.log('Zero')}// 开启定时器let timer = setInterval(show,1000)// 清除定时器clearInterval(timer)
