only join some javascript code example
Example 1: .join javascript
const elements = ['Fire', 'Air', 'Water'];
console.log(elements.join());
// expected output: "Fire,Air,Water"
console.log(elements.join(''));
// expected output: "FireAirWater"
console.log(elements.join('-'));
// expected output: "Fire-Air-Water"
Example 2: join array javascript
<html>
<select multiple class="select-colors">
<option>blue</option>
<option>green</option>
</select>
</html>
<script>
var myColorSelect = $(".select-colors").val().join();
console.log(myColorSelect);
</script>