Html datalist values from array in javascript

This is an old question and already sufficiently answered, but I'm going to throw the DOM method in here anyway for anyone that doesn't like to use literal HTML.

<input name="car" list="anrede" />
<datalist id="anrede"></datalist>

<script>
var mycars = ['Herr','Frau'];
var list = document.getElementById('anrede');

mycars.forEach(function(item){
   var option = document.createElement('option');
   option.value = item;
   list.appendChild(option);
});
</script>

Here's the fiddle.

I'm not sure if I understood your question clearly. Anyway, try this:

var mycars = new Array();
mycars[0] = 'Herr';
mycars[1] = 'Frau';

var options = '';

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

document.getElementById('anrede').innerHTML = options;

<input name="car" list="anrede" />
<datalist id="anrede"></datalist>