JSFiddle - React, Tailwind, and code Playground
by gustavox
HTML
<label class="control-label" for="var3">
<select class="form-control select select-primary select-exemploa" data-toggle="select" name="tvar3" id="var3">
<option>Selecione um valor</option>
<option value="value1">value1</option>
<option value="value2">value2</option>
</select>
</label>
<div id="div1" style="display:none;">div escondida</div>
JavaScript
if (2 > 1){
$("#var3").val('value2');
}
$('#var3').change(function() {
if ($(this).val() == 'value2') {
$("#div1").show();
}
else {
$("#div1").hide();
}
});