javascript - dynamically - jquery remove all options from select




What is the best way to add options to a select from as a JS object with jQuery? (20)

What is the best method for adding options to a <select> from a JavaScript object using jQuery?

I'm looking for something that I don't need a plugin to do, but I would also be interested in the plugins that are out there.

This is what I did:

selectValues = { "1": "test 1", "2": "test 2" };

for (key in selectValues) {
  if (typeof (selectValues[key] == 'string') {
    $('#mySelect').append('<option value="' + key + '">' + selectValues[key] + '</option>');
  }
}

A clean/simple solution:

This is a cleaned up and simplified version of matdumsa's:

$.each(selectValues, function(key, value) {
     $('#mySelect')
          .append($('<option>', { value : key })
          .text(value));
});

Changes from matdumsa's: (1) removed the close tag for the option inside append() and (2) moved the properties/attributes into an map as the second parameter of append().


jQuery

var list = $("#selectList");
$.each(items, function(index, item) {
  list.append(new Option(item.text, item.value));
});

Vanilla JavaScript

var list = document.getElementById("selectList");
for(var i in items) {
  list.add(new Option(items[i].text, items[i].value));
}

  1. $.each is slower than a for loop
  2. Each time, a DOM selection is not the best practice in loop $("#mySelect").append();

So the best solution is the following

If JSON data resp is

[
    {"id":"0001", "name":"Mr. P"},
    {"id":"0003", "name":"Mr. Q"},
    {"id":"0054", "name":"Mr. R"},
    {"id":"0061", "name":"Mr. S"}
]

use it as

var option = "";
for (i=0; i<resp.length; i++) {
    option += "<option value='" + resp[i].id + "'>" + resp[i].name + "</option>";
}
$('#mySelect').html(option);

A compromise of sorts between the top two answers, in a "one-liner":

$.fn.append.apply($('mySelect'),
    $.map(selectValues, function(val, idx) {
        return $("<option/>")
            .val(val.key)
            .text(val.value);
    })
);

Builds up an array of Option elements using map and then appends them all to the Select at once by using apply to send each Option as a separate argument on the append function.



Although the previous answers are all valid answers - it might be advisable to append all these to a documentFragmnet first, then append that document fragment as an element after...

See John Resig's thoughts on the matter...

Something along the lines of:

var frag = document.createDocumentFragment();

for(item in data.Events)
{
    var option = document.createElement("option");

    option.setAttribute("value", data.Events[item].Key);
    option.innerText = data.Events[item].Value;

    frag.appendChild(option);
}
eventDrop.empty();
eventDrop.append(frag);

Be forwarned... I am using jQuery Mobile 1.0b2 with PhoneGap 1.0.0 on an Android 2.2 (Cyanogen 7.0.1) phone (T-Mobile G2) and could not get the .append() method to work at all. I had to use .html() like follows:

var options;
$.each(data, function(index, object) {
    options += '<option value="' + object.id + '">' + object.stop + '</option>';
});

$('#selectMenu').html(options);

I found that this is simple and works great.

for (var i = 0; i < array.length; i++) {
    $('#clientsList').append($("<option></option>").text(array[i].ClientName).val(array[i].ID));
};

I have made something like this, loading a dropdown item via Ajax. The response above is also acceptable, but it is always good to have as little DOM modification as as possible for better performance.

So rather than add each item inside a loop it is better to collect items within a loop and append it once it's completed.

$(data).each(function(){
    ... Collect items
})

Append it,

$('#select_id').append(items); 

or even better

$('#select_id').html(items);

Same as other answers, in jQuery fashion:

$.each(selectValues, function(key, value) {   
     $('#mySelect')
         .append($("<option></option>")
                    .attr("value",key)
                    .text(value)); 
});

That's what I did with two-dimensional arrays: The first column is item i, add to innerHTML of the <option>. The second column is record_id i, add to the value of the <option>:

  1. PHP

    $items = $dal->get_new_items(); // Gets data from the database
    $items_arr = array();
    $i = 0;
    foreach ($items as $item)
    {
        $first_name = $item->first_name;
        $last_name = $item->last_name;
        $date = $item->date;
        $show = $first_name . " " . $last_name . ", " . $date;
        $request_id = $request->request_id;
        $items_arr[0][$i] = $show;
        $items_arr[1][$i] = $request_id;
        $i++;
    }
    
    echo json_encode($items_arr);
    
  2. JavaScript/Ajax

            function ddl_items() {
                if (window.XMLHttpRequest) {
                    // Code for Internet Explorer 7+, Firefox, Chrome, Opera, and Safari
                    xmlhttp=new XMLHttpRequest();
                }
                else{
                    // Code for Internet Explorer 6 and Internet Explorer 5
                    xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
                }
    
                xmlhttp.onreadystatechange=function() {
                if (xmlhttp.readyState==4 && xmlhttp.status==200) {
                    var arr = JSON.parse(xmlhttp.responseText);
                    var lstbx = document.getElementById('my_listbox');
    
                    for (var i=0; i<arr.length; i++) {
                        var option = new Option(arr[0][i], arr[1][i]);
                        lstbx.options.add(option);
                    }
                }
            };
    
            xmlhttp.open("GET", "Code/get_items.php?dummy_time=" + new Date().getTime() + "", true);
            xmlhttp.send();
        }
    }
    

The simple way is:

$('#SelectId').html("<option value='0'>select</option><option value='1'>Laguna</option>");

There's a sorting problem with this solution in Chrome (jQuery 1.7.1) (Chrome sorts object properties by name/number?) So to keep the order (yes, it's object abusing), I changed this:

optionValues0 = {"4321": "option 1", "1234": "option 2"};

to this

optionValues0 = {"1": {id: "4321", value: "option 1"}, "2": {id: "1234", value: "option 2"}};

and then the $.each will look like:

$.each(optionValues0, function(order, object) {
  key = object.id;
  value = object.value;
  $('#mySelect').append($('<option>', { value : key }).text(value));
}); 

This is slightly faster and cleaner.

$.each(selectValues, function(key, value) {
    $('#mySelect').append($("<option/>", {
        value: key,
        text: value
    }));
});

This looks nicer, provides readability, but is slower than other methods.

$.each(selectData, function(i, option)
{
    $("<option/>").val(option.id).text(option.title).appendTo("#selectBox");
});

If you want speed, the fastest (tested!) way is this, using array, not string concatenation, and using only one append call.

auxArr = [];
$.each(selectData, function(i, option)
{
    auxArr[i] = "<option value='" + option.id + "'>" + option.title + "</option>";
});

$('#selectBox').append(auxArr.join(''));

Using the $.map() function, you can do this in a more elegant way:

$('#mySelect').html( $.map(selectValues, function(val, key){
    return '<option value="' + val + '">'+ key + '</option>';
}).join(''));

Yet another way of doing it:

var options = [];    
$.each(selectValues, function(key, value) {
    options.push($("<option/>", {
        value: key,
        text: value
    }));
});
$('#mySelect').append(options);

 var output = [];
 var length = data.length;
 for(var i = 0; i < length; i++)
 {
    output[i++] = '<option value="' + data[i].start + '">' + data[i].start + '</option>';
 }

 $('#choose_schedule').get(0).innerHTML = output.join('');

I've done a few tests and this, I believe, does the job the fastest. :P


$.each(selectValues, function(key, value) {
    $('#mySelect').append($("<option/>", {
        value: key, text: value
    }));
});


if (data.length != 0) {
    var opts = "";
    for (i in data)
        opts += "<option value='"+data[i][value]+"'>"+data[i][text]+"</option>";

    $("#myselect").empty().append(opts);
}

This manipulates the DOM only once after first building a giant string.





html-select