How do I programmatically set the value of a select box element using JavaScript?

Question

I have the following HTML element:

Annual Leave&l

Answer 1

Most of the code mentioned here didn't worked for me!

At last, this worked

window.addEventListener is important, otherwise, your JS code will run before values are fetched in the Options

    window.addEventListener("load", function () {
            // Selecting Element with ID - leaveCode  //
            var formObj = document.getElementById('leaveCode');

            // Setting option as selected
            let len;
            for (let i = 0, len = formObj.length; i < len; i++){
                if (formObj[i].value == '') 
                 formObj.options[i].selected = true;
            }
    });

Hope, this helps!