JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <input type="text" class="checkThis" name="input1" id="input1" value="" />
    <input type="text" name="input2" id="input2" value="" />
    <input type="text" class="checkThis" name="input3" id="input3" value="" />
    <input type="text" class="checkThis" name="input4" id="input4" value="" />
    <input type="text" name="input5" id="input5" value="" />
        <input id="submit_button" type="submit" value="sub" />
    <form>

JavaScript

$(document).ready(function() {
         $('#submit_button').attr('disabled', 'disabled');
    	 
    	 $('input.checkThis').on('change',function(){
    	 	var hasEmptyInput = false;
    	 	$('input.checkThis').each(function(){
    			if ($(this).val() == "") {
                    hasEmptyInput = true;
    				return false;
                }
    		});
    		if(!hasEmptyInput){
    			$('#submit_button').removeAttr('disabled');
            } else {
        		$('#submit_button').attr('disabled', 'disabled');
            }
    	 });
    });