What is easiest way to convert backticks into '<code>' and '</code>'?

Question

What is the easiest way to make this PHP function so that every other backtick becomes a beginning and ending HTML tag, so that:

'in for loops, use `$index` for 0-n values and `$count` for 1-n values'

becomes:

'in for loops, use <code>$index</code> for 0-n values and <code>$count</code> for 1-n values'

e.g.

$line = 'in for loops, use `$index` for 0-n values and `$count` for 1-n values';
echo getFormattedLine($line);

function getFormattedLine($line) {
    return $line; //...str_replace, regular expressions, etc.
}

Answer 1

Seems pretty trivial:

preg_replace('/`(.*?)`/', '<code>$1</code>', $str);