Why does this return empty strings? - php

Question

I want to access the values of an associative array in PHP. I populate the array using the following loop in PHP:
$db = array("a","b","c");
foreach ($db as $q) {
$$q = 'value';
}
This version prints the correct values
foreach ($db as $q) {
echo '<li>'; echo $$q; echo '</li>';
}
\\THIS GIVES ME THE CORRECT OUTPUT <li>value</li><li>value</li><li>value</li>
But I want to access the values through their index
$num = count($db);
for ($i = 0; $i < $num; $i++) {
echo '<li>'; echo $$db[$i]; echo '</li>';
}
\\\\THIS GIVES ME THE WRONG OUTPUT (EMPTY STRINGS <li></li><li></li><li></li>
What is going wrong in the second version? How can I access the values in this associative array through an index correctly?

Answer 1

echo '<li>'; echo $$db[$i]; echo '</li>';
In this line is one $ too much. Write:
echo '<li>'; echo $db[$i]; echo '</li>';
This should do the trick.
PS: You don't have to write echo everytime. Use string concatenation:
echo '<li>' . $db[$i] . '</li>';

Answer 2

You are trying to do something quite strange, anyway the solution to your problem are braces: { }
$num = count($db);
for ($i = 0; $i < $num; $i++) {
echo '<li>'; echo ${$db[$i]}; echo '</li>';
}
Look how braces are resolving the ambiguity, since without them, php wouldn't know if you were referring to ${$db}[$i] or ${$db[$i]}