is $foo'; $ex2 = "Value of var foo is $foo"; $ex3 = <<<HD Value of foo is $foo HD; $ex4 = <<<'ND' Value of foo is $foo 'ND'; echo $ex1 . "\n"; // Value of var foo is $foo echo $ex2 . "\n"; // Value of var foo is bar echo $ex3 . "\n"; // Value of var foo is bar echo $ex4 . "\n"; // Value of var foo is $foo