How to cancel tag a action?

Question

I need to cancel the anchor action after I send an alert. How do I do this?

I tried with e.eventDefault(). I tried with the window.location to redirect the page to the default and I’m not getting the result I want.

 <script type="text/javascript" defer>
    function alertPages() {  
        alert("Página em contrução")

        const a = document.getElementsByTagName('a')
        a.preventDefault()     
    }   
</script>

<a href="./about.html" onclick="alertPages()">About</a>
<a href="./contact.html" onclick="alertPages()">Contato</a>

In other words, when clicking on the link, show the message not redirect to the page.

Answer 1

If what you want is for the page not to follow the normal flow (load the page with the mentioned url), a way to do this would simply change the content of the link if I understood the question correctly:

function alertPages() {
  let a = document.getElementsByTagName('a');

  for (let i = 0; i < a.length; i++) {
    a[i].setAttribute('href', '#');
  }
  alert("Página em contrução");
}

<a href="./about.html" onclick="alertPages()">About</a>
<a href="./contact.html" onclick="alertPages()">Contato</a>