JSFiddle - React, Tailwind, and code Playground

HTML

<select id="select-1" onchange="getArray()">
	<option value="1">Pets</option>
	<option value="2">Foods</option>
	<option value="3">Trees</option>
</select>

<div id="someDiv">

</div>

JavaScript

var array1 = ['cat', 'dog', 'fish', 'bird'];
var array2 = ['taco', 'pizza', 'burger', 'salad'];
var array3 = ['maple', 'elm', 'pine'];

function getArray() {
  var x = document.getElementById("select-1").value;

  //how do I access "arrayx"?
  var y = arrayx[0];

  document.getElementById("someDiv").innerHTML = y;
}