php if statement html option value - php

Question

Suppose you have the following html select statement
<select>
<option value="Newest">Newest</option>
<option value="Best Sellers">Best Sellers</option>
<option value="Alphabetical">Alphabetical</option>
</select>
Now I want to run a php if elseif statement that says,
if (option value = newest) {
// Run this
}
elseif ( option value = best sellers ) {
// Run this
}
etc. But I don't know what to put inside the if elseif statement. In other words instead of 'option value = newest' (which I know is incorrect), what can I put there so that if newest is selected it will execute the if statement, or if best sellers is selected it will execute the elseif statement?

Answer 1

Give name to your select.
<select name="selectedValue">
<option value="Newest">Newest</option>
<option value="Best Sellers">Best Sellers</option>
<option value="Alphabetical">Alphabetical</option>
</select>
in your PHP, you will do:
$_POST['selectedValue'];
if I were you, I would prefer a switch-case incase, there are more than 2 conditions.
Example:
switch($_POST['selectedValue']){
case 'Newest':
// do Something for Newest
break;
case 'Best Sellers':
// do Something for Best seller
break;
case 'Alphabetical':
// do Something for Alphabetical
break;
default:
// Something went wrong or form has been tampered.
}

Answer 2

First put a name on your select:
<select name="demo">
<option value="Newest">Newest</option>
<option value="Best Sellers">Best Sellers</option>
<option value="Alphabetical">Alphabetical</option>
</select>
Then
if ($_POST['demo'] === 'Newest') {
// Run this
}
elseif ( $_POST['demo'] === 'Best Sellers' ) {
// Run this
}
or
switch($_POST['demo']){
case 'Newest' :
//some code;
break;
case 'Best Sellers':
//some code;
break;
default:
//some code if the post doesn't match anything
}

Answer 3

The <select> should have a name attribute, e.g <select name="sortorder">. You could then say
if ($_REQUEST['sortorder'] == 'Newest') {
// TODO sortorder 'Newest' was selected.
}
If you know whether the form data is comming in via HTTP GET or HTTP POST, you could use $_GET['sortorder'] or $_POST['sortorder'] respectively.

Answer 4

I think the read-friendly version would be:
switch($option){
case 'Newest':
runNewestFunction();
break;
case 'Best Sellers':
runBestSellersFunction();
break;
case 'Alphabetical':
runAlphabeticalFunction();
break;
default:
runValidationRequest();
}
also, please add the name attribute <select name="option">