change selected option javascript code example

Example 1: html get selected option javascript

<select id="ddlViewBy">
  <option value="1">test1</option>
  <option value="2" selected="selected">test2</option>
  <option value="3">test3</option>
</select>

<script>
    var e = document.getElementById("ddlViewBy");
	var strUser = e.value; // 2
	var strUser = e.options[e.selectedIndex].text; //test2
</script>

Example 2: javascript select change selected

const options = Array.from(select.options);
options.forEach((option, i) => {
  if (option.value === use_id) select.selectedIndex = i;
});

Example 3: javascript set select option

document.getElementById("mySelectID").value="my_value";
//note: setting value in html directly does not work <select value="my_value">