What would be the code for the uneven numbers?

Answer 1

Just like
if ($a ! = $b)
{
do...
}

Answer 2

Or else you can just use like
For($a=0 ; $a<=50; $a++){
if ($a%2!==0){
echo "uneven";}
}

Answer 3

To print only odd number:-
for ($a=0;$a<=10;$a++)
{
if ($a%2==0)
continue;
echo $a;
}