function?factorial($n){
if($n<=1){
return?1;
}
if($n>1){
return?$n*factorial($n-1);
/*求1!+2!+3!+4!+……+n!*/
function?sum_factorial($n){
$sum?=?0;
for($i=1;$i<=$n;$i++){
$sum+=factorial($i);
return?$sum;
echo?sum_factorial(10);