today 1st time i'm trying ot learn recursion funtion thru online tutorails but stuck at begining stage. i found below code but anything i give value its provide me output: 1
so, i need better explanation of that:

function factorial($n){

    if($n==0){
        return 1;
        }
    return fact($n, 1);
    }

    function fact($i, $j){

        if($i<1){
            return 1;}
            else {
            return fact($i-1, $i*$j);

            }

        }

echo factorial(5);

one more thing, i need clarification of how return fact($i-1, $i*$j); will work to convey single value from two paramaters. any1 pls give me some ideas regading this issue to give up my confusion.

You're nearly there. You weren't multiplying the original number by the resulting factor.

Also, you can simplify your code into a single function. E.g.

function factorial($number, $count = 1)
{
    if($number)
        return $number * factorial($number - 1, ($number - 1) * $count);

    return 1;
}

echo factorial(5);