$proArr = [
1=>'20',//设置得到下标1的概率是20%
2=>'20',
3=>'20',
4=>'0',
5=>'20',
6=>'20',
7=>'0',
8=>'0',
9=>'0',
10=>'0',
];
public static function get_rand($proArr) {//按照概率返回数组的下标
$result = '';
//概率数组的总概率精度
$proSum = array_sum($proArr);
//概率数组循环
foreach ($proArr as $key => $proCur) {
$randNum = mt_rand(1, $proSum);
if ($randNum <= $proCur) {
$result = $key;
break;
} else {
$proSum -= $proCur;
}
}
unset ($proArr);
return $result;
}
