x
 
            
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Fmpq教程(fmpq.com)</title>
</head>
<body>
<p id="demo">单击按钮显示修改年份后的日期。</p>
<button onclick="myFunction()">点我</button>
<script>
function myFunction(){
    var d = new Date();
    d.setFullYear(2020);
    var x = document.getElementById("demo");
    x.innerHTML=d;
}
</script>
</body>
</html>