我已经使用了此代码,但我并不了解输出。我期待输出121。 我希望了解这个特定的功能而不是因子功能。
代码:
(int)scrollView.contentOffset.x % 1024;
输出:
function a($num) {
static $totFac = 1;
if($num > 0){
$totFac = $totFac * $num;
a($num - 1);
}
$totFac++;
return $totFac;
}
$result = a(5);
echo 'result: '.$result;
答案 0 :(得分:3)
首先,5的阶乘被解释为:
5! = 5 x 4 x 3 x 2 x 1 = 120
其次,这是使用递归调用时的阶乘:
function factorial($number) {
if ($number < 2) {
return 1;
} else {
return ($number * factorial($number-1));
}
}
如果你不是指阶乘,那么如果我改变你的功能就会发生这种情况
function a($num) {
static $totFac = 1;
if($num > 0){
$totFac = $totFac * $num;
echo "calc totFac: " . $totFac . "\n";
a($num - 1);
}
$totFac++;
echo "increment totFac: " . $totFac . "\n";
return $totFac;
}
$result = a(5);
echo 'result: '.$result;
这是echo
的输出calc totFac: 5
calc totFac: 20
calc totFac: 60
calc totFac: 120
calc totFac: 120
increment totFac: 120
increment totFac: 121
increment totFac: 122
increment totFac: 123
increment totFac: 124
increment totFac: 125
result: 126
答案 1 :(得分:0)
<?php
function a($num) {
static $totFac = 1;
if($num > 0){
$totFac = $totFac * $num;
echo 'totfac: '.$totFac . "<br>";
return a($num - 1); //you have to return here to stop execution
} else {
$totFac++;
return $totFac;
}
}
$result = a(5);
echo 'result: '.$result;
?>
查看解释说明