JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
<select name="code[]">
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
</select>
<select name="code[]">
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
</select>
<select name="code[]">
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
</select>

JavaScript

var codes = $("select[name='code[]']").serializeArray();
console.log(codes);