[javascript] How to add Drop-Down list (<select>) programmatically?

I want to create a function in order to programmatically add some elements on a page.

Lets say I want to add a drop-down list with four options:

<select name="drop1" id="Select1">
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select>

How can I do that?

Here's an ES6 version, conversion to vanilla JS shouldn't be too hard but I already have jQuery anyways:

function select(options, selected) {_x000D_
  return Object.entries(options).reduce((r, [k, v]) => r.append($('<option>').val(k).text(v)), $('<select>')).val(selected);_x000D_
}_x000D_
$('body').append(select({'option1': 'label 1', 'option2': 'label 2'}, 'option2'));

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>

This code would create a select list dynamically. First I create an array with the car names. Second, I create a select element dynamically and assign it to a variable "sEle" and append it to the body of the html document. Then I use a for loop to loop through the array. Third, I dynamically create the option element and assign it to a variable "oEle". Using an if statement, I assign the attributes 'disabled' and 'selected' to the first option element [0] so that it would be selected always and is disabled. I then create a text node array "oTxt" to append the array names and then append the text node to the option element which is later appended to the select element.

var array = ['Select Car', 'Volvo', 'Saab', 'Mervedes', 'Audi'];_x000D_
_x000D_
var sEle = document.createElement('select');_x000D_
document.getElementsByTagName('body')[0].appendChild(sEle);_x000D_
_x000D_
for (var i = 0; i < array.length; ++i) {_x000D_
  var oEle = document.createElement('option');_x000D_
_x000D_
  if (i == 0) {_x000D_
    oEle.setAttribute('disabled', 'disabled');_x000D_
    oEle.setAttribute('selected', 'selected');_x000D_
  } // end of if loop_x000D_
_x000D_
  var oTxt = document.createTextNode(array[i]);_x000D_
  oEle.appendChild(oTxt);_x000D_
_x000D_
  document.getElementsByTagName('select')[0].appendChild(oEle);_x000D_
} // end of for loop

var sel = document.createElement('select');
sel.name = 'drop1';
sel.id = 'Select1';

var cars = [
  "volvo",
  "saab",
  "mercedes",
  "audi"
];

var options_str = "";

cars.forEach( function(car) {
  options_str += '<option value="' + car + '">' + car + '</option>';
});

sel.innerHTML = options_str;


window.onload = function() {
  document.body.appendChild(sel);
};

Here's an ES6 version of the answer provided by 7stud.

const sel = document.createElement('select');
sel.name = 'drop1';
sel.id = 'Select1';

const cars = [
  "Volvo",
  "Saab",
  "Mercedes",
  "Audi",
];

const options = cars.map(car => {
  const value = car.toLowerCase();
  return `<option value="${value}">${car}</option>`;
});

sel.innerHTML = options;

window.onload = () => document.body.appendChild(sel);

const countryResolver = (data = [{}]) => {
    const countrySelecter = document.createElement('select');
    countrySelecter.className = `custom-select`;
    countrySelecter.id = `countrySelect`;
    countrySelecter.setAttribute("aria-label", "Example select with button addon");

    let opt = document.createElement("option");
    opt.text = "Select language";
    opt.disabled = true;
    countrySelecter.add(opt, null);
    let i = 0;
    for (let item of data) {
        let opt = document.createElement("option");
        opt.value = item.Id;
        opt.text = `${i++}. ${item.Id} - ${item.Value}(${item.Comment})`;
        countrySelecter.add(opt, null);
    }
    return countrySelecter;
};

I have quickly made a function that can achieve this, it may not be the best way to do this but it simply works and should be cross browser, please also know that i am NOT a expert in JavaScript so any tips are great :)

Pure Javascript Create Element Solution

function createElement(){
    var element  = document.createElement(arguments[0]),
        text     = arguments[1],
        attr     = arguments[2],
        append   = arguments[3],
        appendTo = arguments[4];

    for(var key = 0; key < Object.keys(attr).length ; key++){
        var name = Object.keys(attr)[key],
             value = attr[name],
             tempAttr = document.createAttribute(name);
             tempAttr.value = value;
        element.setAttributeNode(tempAttr)
    }
    
    if(append){
        for(var _key = 0; _key < append.length; _key++) {
            element.appendChild(append[_key]);
        }
    }

    if(text) element.appendChild(document.createTextNode(text));

    if(appendTo){
        var target = appendTo === 'body' ? document.body : document.getElementById(appendTo);
        target.appendChild(element)
    }       

    return element;
}

lets see how we make this

<select name="drop1" id="Select1">
  <option value="volvo">Volvo</option>
  <option value="saab">Saab</option>
  <option value="mercedes">Mercedes</option>
  <option value="audi">Audi</option>
</select>

here's how it works

    var options = [
        createElement('option', 'Volvo', {value: 'volvo'}),
        createElement('option', 'Saab', {value: 'saab'}),
        createElement('option', 'Mercedes', {value: 'mercedes'}),
        createElement('option', 'Audi', {value: 'audi'})
    ];


    createElement('select', null, // 'select' = name of element to create, null = no text to insert
        {id: 'Select1', name: 'drop1'}, // Attributes to attach
        [options[0], options[1], options[2], options[3]], // append all 4 elements
        'body' // append final element to body - this also takes a element by id without the #
    );

this is the params

createElement('tagName', 'Text to Insert', {any: 'attribute', here: 'like', id: 'mainContainer'}, [elements, to, append, to, this, element], 'body || container = where to append this element');

This function would suit if you have to append many element, if there is any way to improve this answer please let me know.

edit:

Here is a working demo

JSFiddle Demo

This can be highly customized to suit your project!

it's very simple yet tricky but here is what you wanted, hope it's helpful : this function generates a select list from 1990 to 2018 i think this example can help ya, if you want to add any other value just change value of x and y ;)

function dropDown(){
    var start = 1990;
    var today = 2019;
    document.write("<select>");
    for (var i = start ; i <= today; i++)
    document.write("<option>" + i + "</option>");
}
document.write("</select>");

dropDown();