$variables = 'are set this way';
$var = "they can be set this way too";
echo "$var"; // would output the contents of that variable, but
echo '$var'; // would output $var and not it's contents
echo $var; // is the proper way of outputting variables.
// this is a comment
# this is also one
/* as
well
as
this */
$x = 10; // numbers don't need to be in quotes or apostrophes.
if ($x == 10) { // == means equal to. there's also ===
echo "do this"; //every line that isn't a conditional if, else, which, etc... needs to have a semicolon
} else {
echo 'this shouldn\'t happen'; // have to escape ( \ ) the apostrophe or the string would end there.
}