JSFiddle - React, Tailwind, and code Playground

HTML

<div class="gallery">
        <div>
            <img src="content/imggallery/img1.jpg" class="oldimg" value="0">
        </div>
        <div>
            <img src="content/imggallery/img2.jpg" class="oldimg" value="1">
        </div>
        <div>
            <img src="content/imggallery/img3.jpg" class="oldimg" value="2">
        </div>
    </div>

JavaScript

var imageData = new Array (3);
imageData[0]="0.jpg";
imageData[1]="1.jpg";
imageData[2]="2.jpg";
$(".oldimg").click(function(){
       var value= $(this).attr("value");
       imageData[value]; // get value 
    alert(imageData[value]);
});