Analysis of two usages of the a tag in HTML post request

<a href="https://www.jb51.net/" class="a_post">Initiate POST request</a>

$(".a_post").on("click",function(event){
    event.preventDefault(); // Make the method of a invalid, that is, it cannot be adjusted to the URL in href (https://www.cnblogs.com/)
    $.ajax({
           type: "POST",
           url: "url address",
           contentType:"application/json",
           data: JSON.stringify({param1:param1,param2:param2}), //parameter list dataType:"json",
           success: function(result){
              //Operation after request is correct},
           error: function(result){
              //Operation after request failure}
    });
});

<form id="_form" method="post" action="target">
  <input type="hidden" name="name" value="value" /> 
  <a onclick="document.getElementById('_form').submit();">Click Submit</a>
</form>