JSFiddle - React, Tailwind, and code Playground

HTML

<form id="myform" action="page.php">
    <input type="text" name="a" value="Default 1" />
    <br/>
    <input type="text" name="b" value="" />
    <br/>
    <input type="text" name="c" value="Default 3" />
    <br/>
    <input type="text" name="d" value="" />
    <br/>
    <input type="text" name="e" value="Default 5" />
    <br/>
    <input type="submit" value="send data">
</form>

JavaScript

$("#myform").submit(function (event) {
    event.preventDefault();
    var dataArr = {};

    $.each($("form > input[name]"), function (key, value) {
        if ($(this).val() != "") {
            dataArr[$(this).attr('name')] = $(this).val();
        }
    });

    $.post($(this).attr('action'), dataArr);
    alert("Form submitted!");

});