myFunction(){
      //data here
}

<?php 
$data ={
?>
test
<?php
}
myFunction($test);
?>

<?php
function myFunction($input) {
      $output = strtolower($input);
      return $output;
}
 
$data = 'TEST';
$result = myFunction($data);
 
echo $result;
?>

<?php
checkConfig(){
?>
<input type="text" name="input" />
<?php
}
?>

<?php 
function check($d){
   require('config.php'); // contains $boldtext = true;
   if($boldtext){
         return "<b>".$d."</b>";
    }
}?>

<?php class data{function get(){  ?>

	This is the text that will go through the check() function

<?php } function ret($string){echo $string;}}$data = new data(); ?>
 
 
<?php
$data->ret(check($data->get()));
?>

<?php 
//function that gets html
function getHTML($container_function){
	//johndm.com - gets html that results from
	//a function. example usage:
	//		<?php function foo(){ ?|> bar <?php } ?|>
	//		echo "<b>".getHTML("foo")."</b>";
 
	ob_start();ob_clean(); //start buffer
	call_user_func($container_function); //call container function
	$data=ob_get_contents(); //get data
	ob_end_clean(); //remove output from function
	return $data; //return html
 
} 
 
//example usage
 
function foo(){ ?>
<b>foo</b>
<?php } 
$d=getHTML("foo"); 
 
//now that the html outputted by the
//function is in a string, you can do anything
//to it you could do to a string.
 
echo "i am a ".$d." bar";
echo "<br />";
echo "i am ".strlen($d)." chars long";
echo "<br />";
echo "i have ".substr_count($d,">")." '>'s in me";
echo "<br />";
echo "my html looks like this: ".htmlentities($d);
 
//not only can it get html that is not inside
//of php tags, it can also let you modify 
//echo/printed data from a function also.
?>
 

<?php
function myfunction($buffer) {
	return str_replace('hello', 'goodbye', $buffer);
}
$mystuff = ob_start("myfunction");
?>
I am here to say hello
<?php
ob_end_flush();
?>