jQuery addClass example
Change class name on click in jQuery
HTML
<select id="imgIndexInput">
<option value='0'>Image 0</option>
<option value='1'>Image 1</option>
<option value='2'>Image 2</option>
<option value='3'>Image 3</option>
<option value='4'>Image 4</option>
<option value='5'>Image 5</option>
</select>
<div id="app">
<img class="img" src="https://imgur.com/ANKvzxJ.png"/>
<img class="img" style="display: none;" src="https://imgur.com/mzrMmLp.png"/>
<img class="img" style="display: none;" src="https://imgur.com/ztfkAMz.png"/>
<img class="img" style="display: none;" src="https://imgur.com/TmxqpkR.png"/>
<img class="img" style="display: none;" src="https://imgur.com/Z1WrT8Z.png"/>
<img class="img" style="display: none;" src="https://imgur.com/alAHUNN.png"/>
<img class="img" style="display: none;" src="https://imgur.com/IN5oWqi.png"/>
<img class="img" style="display: none;" src="https://imgur.com/2CaUJze.png"/>
</div>
CSS
.img {
width: 500px;
height: 300px;
}
JavaScript
let imgIndex = 0;
$('#imgIndexInput').change(function() {
$('img').hide();
$($('img')[this.value]).show();
});