<?php
function distance($vect1, $vect2)
{
if (!is_array($vect1) || !is_array($vect2)) {
return NULL;
}
if (count($vect1) != count($vect2)) {
return NULL;
}
for ($i=0; $i<count($vect1); $i++) {
$c1 = $vect1[$i]; $c2 = $vect2[$i];
$d = 0.0;
if (!is_numeric($c1)) {
trigger_error("Coordinate $i in vector 1 is not a number, using zero",
E_USER_WARNING);
$c1 = 0.0;
}
if (!is_numeric($c2)) {
trigger_error("Coordinate $i in vector 2 is not a number, using zero",
E_USER_WARNING);
$c2 = 0.0;
}
$d += $c2*$c2 - $c1*$c1;
return $d;
echo sqrt($d);
}
}
// variabile non definita, genera un warning
// definisce dei vettori
$b = array(5.5, 4.3);
$c = array(1, 3);
// genera un errore utente
distance($c, $b) ;
// un'altro errore utente
distance($b, "i am not an array") ;
// genera un warning
?>