$bob = 6;
echo "Bob=$bob"; // outputs Bob=6 
echo 'Bob=$bob'; // outputs Bob=$bob

<p> A paragraph. Let's hop into interpretive mode: <?php
print "hi there"; ?> back to copy mode </p>

<p> A paragraph. Let's hop into interpretive mode to echo 
the variable $foo: <?= $foo ?> 
back to copy mode </p>

$a = "hello";
//Heredocs
$str = <<<EOD
This string that lives
on multiple lines uses heredocs
syntax. $a interpolation happens 
EOD;
echo $str;
//Nowdocs
$str2 = <<<'EOD2'
$a interpolation doesn't happens
EOD2;
echo $str2;

//if
if ($a) print "hello";
if ($a) {
   print "hello";
   print "there";
}
if ($a) {
   $b = 1;
   echo  $b;
} else if ($b) {
   $b = 2;
   echo $b;
} else {
   $c = 1;
   echo $c;
}
//switch case:
switch($a)
{
   case 5:
      echo "hello";
      /* if $a matches the label (5 in this case)
         then execute the code after it;
       */
      break; //if hit then jump out of switch
   case "a label made from a string":
      echo "weird labels still work";
      break;
   default:
      echo "if all else fails do this";
}

for($a = 0; $a<10; $a++){echo "hello $a";}

while(!$var) { /*do something*/}

do {/*do something */} while (!$var);

<?php if ($the_world_is_round == true): ?>
The world is not flat.
<?php endif; ?>

$a = array("hi", 1, 2);
//for PHP >= 5.4 you can also use the syntax:
$a = ["hi", 1, 2];

$b = ["hi", [1,2], 2];
$c = ["a" => "c"];

echo $a[0]." ".$c['a'];

foreach($arr as $var){echo $var;}

foreach($assoc_arr as $key => $value){echo "Key $key Value $value";}

list($first, $second, ) = $arr; 
//$first will be $arr[0], $second will be $arr[1].