不断在控制台输出数字
var i = 0;
setInterval(function(){
i++;
console.log(i);
},1000)
元素透明度渐变效果
<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
#someDiv{
width:100px;
height:100px;
background-color:red;
opacity:1;
}
</style>
</head>
<body>
<div id="someDiv"></div>
<script>
var div = document.getElementById("someDiv");
var opacity = 1;
var fade = setInterval(function(){
if(opacity>0){
opacity -= 0.05;
div.style.opacity = opacity;
}else{
clearInterval(fade)
};
},1000);
</script>
</body>
</html>
