PHP counter increment in a while loop

Question

Im having a problem incrementing a counter in one of my while loops basically i just want to alternate between two image links that were fetched in my database but my counter wo

Answer 1

$i  = 0;
while($i<5) {
    $alternateVal   = $i%2==0 ? "type1" : "type2";
    echo $alternateVal;
    $i++;
}

Above is an example to overview alternate values.