Question

In generating a select tag for a Boolean value, I use the following code:

<select name="name" id="id">
    <option value="0"<?php if(empty($value)): ?> selected="selected"<?php endif; ?>>Off</option>
    <option value="1"<?php if($value): ?> selected="selected"<?php endif; ?>>Off</option>
</select>

So, the question is, will this map correctly, so that at no point, both the options will have a selected="selected" property?

Answer 1

The only reason I see to use empty() here is to avoid warnings in case $value is not set. But in this case you get the warning next line. It’s more common and prettier to use ! to negate booleans otherwise.

But to answer your question, yes, your assumption is safe.

Update: The documentation explicitly states that

empty() is the opposite of (boolean) var, except that no warning is generated when the variable is not set.