<?php
function byval($num1,$num2)
{
$num1++;
$num2++;
}
$n1=10;
$n2=20;
echo "<br>Original Value Of n1= $n1 & n2= $n2<b>";
byval($n1,$n2);
echo "<br>By Value Value Of n1= $n1 & n2= $n2<b>";
?>
Output :-Original Value Of n1= 10 & n2= 20
By Value Value Of n1= 10 & n2= 20