PHP Strings
Leading zeroes
// Prints a leading zero if the `$number` is a single digit.
echo sprintf('%02d', $number);
Variables in strings
Variable
echo "The quick brown fox $my_variable over the lazy dog.\n";
Array
echo "The quick brown fox {$my_array['animal_action']} over the lazy dog.\n";
Class property
echo "The quick brown fox $my_class->my_text_var over the lazy dog.\n";