JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <input type='text' value='' />
    <input type='submit' />
</form>

JavaScript

$('form').submit(function() {
    
   var error;
    
    if ( !$('input').val() ) {
        error = true
    }
    
    if (error) {
         alert('there are errors')
         return false
    }
    
});