how to show selected value in dropdown in html code example

Example 1: javascript to get value of dropdown

var e = document.getElementById("elementId");
var value = e.options[e.selectedIndex].value;
var text = e.options[e.selectedIndex].text;

Example 2: selected dropdown value

Plain JavaScript:
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var e = document.getElementById("elementId");
var value = e.options[e.selectedIndex].value;
var text = e.options[e.selectedIndex].text;
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jQuery:
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$("#elementId :selected").text(); // The text content of the selected option
$("#elementId :selected").val(); // The value of the selected option