抽奖功能

prize.php

function get_rand($proArr) {
    $res = '';

    //改了数组的总概率精度
    $proSum = array_sum($proArr);

    //概率数组循环
    foreach ($proArr as $k => $v) {
        $randNum = mt_rand(1, $proSum);
        if ($randNum <= $v) {
            $res = $k;
            break;
        } else {
            $proSum -= $v;
        }
    }

    unset($proArr);

    return $res;
}

$prize_arr = [
    0 => [
        'id'    => 1,
        'prize' => '平板电脑',
        'v'     => 1
    ],
    1 => [
        'id'    => 2,
        'prize' => '数码相机',
        'v'     => 5
    ],
    2 => [
        'id'    => 3,
        'prize' => '智能能手机',
        'v'     => 10
    ],
    3 => [
        'id'    => 4,
        'prize' => '数码相机',
        'v'     => 40
    ],
    4 => [
        'id'    => 5,
        'prize' => '谢谢惠顾',
        'v'     => 60
    ],
];

//实现抽奖功能
function setPrize($prize_arr) {
    $arr = array();
    $pr = array();
    foreach ($prize_arr as $key => $val) {
        $arr[$val['id']] = $val['v'];
    }
    $rid = get_rand($arr);

    //中奖项
    $res['yes'] = $prize_arr[$rid - 1]['prize'];
    unset($prize_arr[$rid - 1]);
    shuffle($prize_arr);
    for ($i = 0; $i < count($prize_arr); $i++) {
        $pr[] = $prize_arr[$i]['prize'];
    }
    $res['no'] = $pr;
    echo json_encode($res, true);
}

setPrize($prize_arr);