URL is redirecting to "www.example.com/undefined"

Question

There is a three level dependent drop-down(country-state-city) using jquery, AJAX and JSON. To redirect the user to a page after he selected city (www.example.com/city, the city is numeric value here) I used the following code, HTML

<select name="city" id="city" class="form-control input-lg" onchange="onfuct()">
 <option value="">Select City</option>
</select>

The javascript is here

var value_1 = document.getElementByID('city').value;

function onfuct () {
   window.location.replace("www.example.com"/+value_1);
}

Can somebody help me out it is redirecting to "www.example.com/undefined"

Can you share what your select options looks lik? Most likely you are not setting values right. — Dipen Shah, Oct 04 '20 at 06:31
Getting `undefined` from `"url"+/value_1` so clearly `value_1` is `undefined` so clearly `var value_1 =` isn't how you "get value from select" - so: https://stackoverflow.com/search?q=%5Bjavascript%5D+get+value+from+select — freedomn-m, Oct 04 '20 at 09:13
@DipenShah https://www.webslesson.info/2017/05/json-dynamic-dependent-select-box-using-jquery-and-ajax.html i copied it from here. — madhurkant, Oct 13 '20 at 16:04

score 1 · Answer 1 · answered Oct 04 '20 at 06:44

value does not exist on <select>, you need to do a bit more work to obtain the selected value. Also, JavaScript is case-sensitive; getElementByID is NOT getElementById

// Get the element from DOM
const city = document.getElementById('city');

/*
  Move event listeners to JavaScript like

  city.addEventListener('onchange', onfuct)

*/

function onfuct() {
  // city.options returns the option elements
  let selectedCity = city.options[city.selectedIndex].value;

  console.log("www.example.com/" + selectedCity);
}

<select name="city" id="city" class="form-control input-lg" onchange="onfuct()">
  <option value="stockholm">Stockholm</option>
  <option value="new-york">New York</option>
  <option value="oslo">Oslo</option>
</select>

URL is redirecting to "www.example.com/undefined"

1 Answers1