Hola a todos alguien sabe si esto se puede adaptar para un tercer select y array?
Código HTML:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="content-type" content="text/xhtml; charset=utf-8" />
<title>Dynamic Select Statements</title>
<script type="text/javascript">
//<![CDATA[
// array of possible countries in the same order as they appear in the country selection list
var countryLists = new Array(4)
countryLists["empty"] = ["Select a Country"];
countryLists["North America"] = ["Canada", "United States", "Mexico"];
countryLists["South America"] = ["Brazil", "Argentina", "Chile", "Ecuador"];
countryLists["Asia"] = ["Russia", "China", "Japan"];
countryLists["Europe"]= ["Britain", "France", "Spain", "Germany"];
/* CountryChange() is called from the onchange event of a select element.
* param selectObj - the select object which fired the on change event.
*/
function countryChange(selectObj) {
// get the index of the selected option
var idx = selectObj.selectedIndex;
// get the value of the selected option
var which = selectObj.options[idx].value;
// use the selected option value to retrieve the list of items from the countryLists array
cList = countryLists[which];
// get the country select element via its known id
var cSelect = document.getElementById("country");
// remove the current options from the country select
var len=cSelect.options.length;
while (cSelect.options.length > 0) {
cSelect.remove(0);
}
var newOption;
// create new options
for (var i=0; i<cList.length; i++) {
newOption = document.createElement("option");
newOption.value = cList[i]; // assumes option string and value are the same
newOption.text=cList[i];
// add the new option
try {
cSelect.add(newOption); // this will fail in DOM browsers but is needed for IE
}
catch (e) {
cSelect.appendChild(newOption);
}
}
}
//]]>
</script>
</head>
<body>
<noscript>This page requires JavaScript be available and enabled to function properly</noscript>
<h1>Dynamic Select Statements</h1>
<label for="continent">Select Continent</label>
<select id="continent" onchange="countryChange(this);">
<option value="empty">Select a Continent</option>
<option value="North America">North America</option>
<option value="South America">South America</option>
<option value="Asia">Asia</option>
<option value="Europe">Europe</option>
</select>
<br/>
<label for="country">Select a country</label>
<select id="country">
<option value="0">Select a country</option>
</select>
</body>
</html>
Fuente
El ejemplo trae solo dos select (Continente, país.) habria la posibilidad de que funcione un tercero? (Continente, país, cuidad)
Ejemplo