js selected option code example

Example 1: make select option selected javascript

document.getElementById('personlist').getElementsByTagName('option')[11].selected = 'selected'

Example 2: js select option in form

<form name="AddAndEdit">
   <select name="list" id="personlist">
      <option value="P1">Person1</option>
      <option value="P2">Person2</option>
      <option value="P3">Person3</option>
   </select>
</form>

Example 3: use js to get select value

// reference to 'scripts' select list 
// used throughout the examples below
var sel = document.getElementById('scripts');

// display value property of select list (from selected option)
console.log( sel.value );

Example 4: js select option value when selected

(function() {
    
    // get references to select list and display text box
    var sel = document.getElementById('scripts');
    var el = document.getElementById('display');


    function getSelectedOption(sel) {
        var opt;
        for ( var i = 0, len = sel.options.length; i < len; i++ ) {
            opt = sel.options[i];
            if ( opt.selected === true ) {
                break;
            }
        }
        return opt;
    }

    // assign onclick handlers to the buttons
    document.getElementById('showVal').onclick = function () {
        el.value = sel.value;    
    }
    
    document.getElementById('showTxt').onclick = function () {
        // access text property of selected option
        el.value = sel.options[sel.selectedIndex].text;
    }

    document.getElementById('doLoop').onclick = function () {
        var opt = getSelectedOption(sel);
        el.value = opt.value;
    }
    
}());
// immediate function to preserve global namespace