PHP, JS, Processing

Funzione

echo '<form action="function.php#tbox1" method="post">
<input type="text"  name="numOne" value="'.($_POST['numOne']?$_POST['numOne']:"Scrivi un numero").'">
<input type="text"  name="numTwo" value="'.($_POST['numTwo']?$_POST['numTwo']:"Scrivi un numero").'">
<input type="submit"  value="Invia" >
</form>';

function  test($parOne, $parTwo){

if(is_numeric($parOne) && is_numeric($parTwo)){$sum=$parOne+$parTwo;  $string = 'la somma dei due numeri &egrave;: '.$sum;}else{$string = 'Pls. inserisci due numeri!';}

	return $string; 
}

echo test($_POST['numOne'], $_POST['numTwo']);

definizione per recursione  click: vedi codice

$folderPath = "../step_prog";
function readFolder( $path ) {
 
  // Open the folder
  if ( !( $dir = opendir( $path ) ) ) die( "Can't open $path" );
  $filenames = array();
 
  // Read the contents of the folder, ignoring '.' and '..', and
  // appending '/' to any subfolder names. Add all the files and
  // subfolders to the $filenames array.
 
  while ( $filename = readdir( $dir ) ) {
    if ( $filename != '.' && $filename != '..' ) {
      if ( is_dir( "$path/$filename" ) ) $filename .= '/';
      $filenames[] = $filename;
    }
  }
 
  closedir ( $dir );
 
  // Sort the filenames in alphabetical order
  sort( $filenames );
 
  // Display the filenames, and process any subfolders
  $string = '';
  $string .=  "<ul>";
 
  foreach ( $filenames as $filename ) {
    $string .=  "<li>". $filename;
    if ( substr( $filename, -1 ) == '/' ){$string .=' '.  readFolder( $path."/" . substr( $filename, 0, -1 ) );}
    $string .=  "</li>";
  }
 
  $string .=  "</ul>";

  return $string; 
}
echo "<h2>file e cartelle in  ".$folderPath.":</h2>";
echo readFolder( $folderPath );

ricorsione: un classico esempio: il fattoriale  click: vedi codice

 
function factorialString($n){
	$out = 0; 
        $comp = '';
	$string = ''; 
if ($n == 0) {
	$out = 1;
	$comp = 1; 
	$string = "caso base: <br> 0. factorial(0)  =  1, risultato &egrave; 1<br>";
}else{
  	$call = $n-1; 
        $out = ($n * (factorialString($call)[0]));
        $comp = $n . '*' . factorialString($call)[1];
 
        $string = factorialString($call)[2] .$n.". factorial(".$n.") =  ".$n." * factorial(".$call.") = ". factorialString($call)[1].", risultato &egrave; ".$out."<br>";
        
}
  $r = array($out,$comp,$string);
  return $r;
}
echo factorialString(11)[2];

Funzione ricorsiva - Frattale

float theta; 
float a = 0;

void setup() {
  size(640, 360);
}

void draw() {
  background(255);
  frameRate(3);
  stroke(240,0,0);
  // Let's pick an angle 0 to 90 degrees based on the mouse position
  if (a < 360){ a = a+5; 
	}else{ a=0; }
  // Convert it to radians
  theta = radians(a);
  // Start the tree from the bottom of the screen
  translate(width/2,height);
  // Draw a line 120 pixels
  line(0,0,0,-100);
  // Move to the end of that line
  translate(0,-100);
  // Start the recursive branching!
  branch(100);
}

void branch(float h) {
  // Each branch will be 2/3rds the size of the previous one
  h *= 0.66;
  // All recursive functions must have an exit condition!!!!
  // Here, ours is when the length of the branch is 2 pixels or less
  if (h > 2) {
    pushMatrix();    // Save the current state of transformation (i.e. where are we now)
    rotate(theta);   // Rotate by theta
    line(0, 0, 0, -h);  // Draw the branch
    translate(0, -h); // Move to the end of the branch
    branch(h);       // Ok, now call myself to draw two new branches!!
    popMatrix();     // Whenever we get back here, we "pop" in order to restore the previous matrix state
    
    // Repeat the same thing, only branch off to the "left" this time!
    pushMatrix();
    rotate(-theta);
    line(0, 0, 0, -h);
    translate(0, -h);
    branch(h);
    popMatrix();
  }
}