Get max and min value in array without using function in PHP

<?php

$array = array(2,4,8,5,1,6);
$max = $array[0];
$min = $array[0];
foreach($array as $val)
{
    //For max Value
    if($max<$val)
    {
        $max = $val;
    }

    //For min value
    if($min>$val)
    {
        $min = $val;
    }
   
}
echo "Max value is: ".$max;
echo "<br>";
echo "Min value is: ".$min;

?>

Factorial Number Programming using PHP

<?php

$num = 5;
$factorial = 1;
for($i = 1; $i<=$num; $i++)
{
    $factorial  = $factorial * $i;
}
echo $factorial;
?>

Print prime number in given length using PHP

<?php

$num = 5;

for($j = 2;$j<=$num;$j++)

{

    for($k=2;$k<=$j;$k++)

    {

        if($j%$k==0)

        {

            break;

        }

    }

    if($j==$k)

    {

        echo $k."<br>";

    }

}

?>

Find number is prime or not using PHP

<?php
$num = 17;
$prime=true;
for($i=2;$i<=$num/2;$i++)
{
    $j = $num % $i;
    if($j==0){
        $prime=false;
        break;
    }
}
if($prime==true){
    echo "No is prime<br/>";
}
else{
    echo "No is not prime";
}

?>