第一种写法:

<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script>
//阻止超链接的默认的跳转:return false

</script>
<a href="http://wwww.baidu.com" onclick="alert('哎呀,我被点了');return false">百度</a>
</body>
</html>

第二种写法:
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script>
function f1(){
  alert("哎呀,好漂亮啊!");
  return false
}
//阻止超链接的默认的跳转:return false

</script>
<a href="http://wwww.baidu.com" onclick="return f1()">百度</a>
</body>
</html>
第三种写法:
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>

<a href="http://wwww.baidu.com" id=“ak”>百度</a>
<script>
  document.getElementById("ak").onclick = function(){
  alert("哎呀,被点了");
  return false;
}
</script>
</body>
</html>