还是php的概率的问题，求解说
概率计算函数，网上搜了很多都是这个，不过没看得懂这函数，求解下过程是怎样的~
这数组是id和相应的概率。
<br> Array<br> (<br> ????[1] => 1<br> ????[2] => 5<br> ????[3] => 10<br> ????[4] => 12<br> ????[5] => 22<br> ????[6] => 50<br> )
为什么这样就能得到概率奖项的id呢？？get_rand($arr);
function get_rand($proArr) { <br>
????$result = ''; <br>
????//概率数组的总概率精度 <br>
????$proSum = array_sum($proArr); <br>
????//概率数组循环 <br>
????foreach ($proArr as $key => $proCur) { <br>
????????$randNum = mt_rand(1, $proSum); <br>
????????if ($randNum <= $proCur) { <br>
????????????$result = $key; <br>
????????????break; <br>
????????} else { <br>
????????????$proSum -= $proCur; <br>
????????} <br>
????} <br>
????unset ($proArr); <br>
????return $result; <br>
}
