JSFiddle - React, Tailwind, and code Playground

HTML

<select id="my-select">
    <option val="1">1</option>
    <option val="2">2</option>
</select>

JavaScript

(function( $ ) { 
	$.fn.userSelect = function(value) {
		this.each(function(){
		  alert(this.innerHTML);  // undefined
		  this.style.webkitUserSelect = value;
		  this.style.mozUserSelect = value;
		  this.style.oUserSelect = value;
		  this.style.msUserSelect = value;
		  this.style.userSelect = value;
		});
	};
})(jQuery);

$(document).ready(function(){
    $('#my-select').userSelect();
});