JSFiddle - React, Tailwind, and code Playground
by John Doe
HTML
<select id='source'>
<option value='s1'>s1</option>
<option value='s2'>s2</option>
<option value='s3'>s3</option>
<option value='s4'>s4</option>
<option value='s5'>s5</option>
</select>
<select id='target'>
<option value='1'>t1</option>
<option value='2'>t2</option>
<option value='3'>t3</option>
<option value='4'>t4</option>
<option value='5'>t5</option>
</select>
<br/>
<input type='button' id='move' value='Move Source to Target'/>
JavaScript
$("#move").click(function(){
var tempVal = $("#source").val();
var tempText = $("#source option:selected").text();
$("#target").append("<option value='"+tempVal+"'>"+tempText+"</option>");//copy
$("#source option[value='"+tempVal+"']").remove();
});