运算符的优先级

$a = 3;
$b = 3;
if($a = 5 || $b = 5){
$a++;
$b++;
}
echo $a.'和'.$b;
var_dump($a);
var_dump($b);
echo '<hr>';

 

$a = 3;
$b = 3;
if($a = 5 && $b = 5){
$a++;
$b++;
}

echo $a.'和'.$b;
var_dump($a);
var_dump($b);
echo '<hr>';