Javascript Represent an integer as any string

If you have a dropdown (i.e. select element), the value attribute of the option elements are independent of the text displayed to the user.

You can have an

<option value="value that you want to have in code">
    Text that your user should see
</option>`

If the select needs to be populated from an array, then you can use JavaScript to create DOM elements and add them to the corresponding select node.

HTML

<select id="selectbox"></select>

JS

array.forEach(function(e) {
    var option = document.createElement('option');
    option.value = e;
    option.textContent = e ? e : 'Select';
    document.getElementById('selectbox').appendChild(option);
});

Should generate

<select>
  <option value="10">10></option>
  <option value="5">5></option>
  <option value="0">Select</option>
  <option value="-5">-5></option>
  <option value="-10">-10></option>
</select>

You can use the value property of the options:

<select id="my-select">
   <option value="0">Select</option>
   <option value="10">10</option>
   <option value="-5">-5</option>
</select>

Javascript to get current value:

var ele = document.getElementById('my-select');
var myValue = ele.options[ele.selectedIndex].value;

Simple as that:

var selectValues = [10, 5, 0, -5, -10];
$.each(selectValues, function(key, value) {   
     if(value==0){
       $('#cars')
         .append($("<option ></option>")
         .attr("value",value)
         .text("Select")); 
     }else{
       $('#cars')
         .append($("<option ></option>")
         .attr("value",value)
         .text(value)); 
     }
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<form action="demo_form.asp">
  <select id="cars" name="cars">
    
  </select>
  <input type="submit" value="Submit">
</form>