如何从二维数组中随机取每组相同ID的一条信息？，先谢谢了！

[只是喜欢]

$data = array(
            array(
                "eid" => "2","name" => "A1"
            ),
            array(
                "eid" => "2","name" => "A2"
            ),
            array(
                "eid" => "2","name" => "A3"
            ),
            array(
                "eid" => "8","name" => "B1"
            ),
            array(
                "eid" => "8","name" => "B2"
            ),
            array(
                "eid" => "5","name" => "C1"
            ),
            array(
                "eid" => "5","name" => "C2"
            )
    );

想要的结果：
$data = array(
array(
"eid" => "2","name" => "A2"
),
array(
"eid" => "8","name" => "B2"
),
array(
"eid" => "5","name" => "C1"
)
);

相同的eid随机取1条（数据多是随机取不同的多条，比如相同的eid随机取5条）

该怎么写呢，先谢谢了！

[只是喜欢]

首先很感谢两位大神，我试了下，发现点小问题，我数组有50个，但是最终只输出了8个，不懂是哪里的原因？

[只是喜欢]

而且选出来的有重复

[xuzuning]

你要求的是： 相同的eid随机取1条 只需将 $res = array_merge($res, array_slice($v, 0,ceil(log(count($v))))); 改为 $res[] = $v[0]; 即可 数据多时随机取不同的多条，比如相同的eid随机取5条 如何判断 数据多，你并没有说，我只是给出了一种可能性，和组装的方法而已 $res = array_merge($res, array_slice($v, 0,ceil(log(count($v))))); 想来并不伤大雅 shuffle 只是打乱数组，并不会对数组原有的值产生影响 如果说是 选出来的有重复，那么只能说明你的数组本来就是有重复的

[xuzuning]

$data = array(
            array(
                "eid" => "2","name" => "A1"
            ),
            array(
                "eid" => "2","name" => "A2"
            ),
            array(
                "eid" => "2","name" => "A3"
            ),
            array(
                "eid" => "8","name" => "B1"
            ),
            array(
                "eid" => "8","name" => "B2"
            ),
            array(
                "eid" => "5","name" => "C1"
            ),
            array(
                "eid" => "5","name" => "C2"
            )
    );
foreach($data as $v) $tmp[$v['eid']][] = $v;
$res = [];
foreach($tmp as $v) {
  shuffle($v);
  $res = array_merge($res, array_slice($v, 0,ceil(log(count($v)))));
}
print_r($res);

[只是喜欢]

很感谢老大啊，打了那么多字，回答好认真，真的很谢谢！ 现在是这样，比如总数组有50个，是由3种不同的eid数据组成，A组eid数据有15条，B组eid数据有18条，C组eid数据有17条 现在想从50个的总数据中选择20组， 这20组数据，每种eid相同的组随机取6条，3x6=18，不够20条随机多取2条，拼够20条就好 不懂我描述是否清楚，老大能帮看下怎么改写吗？先谢谢了！

[只是喜欢]

改成这样已经实现了，再次感谢！

foreach($list as $v) $tmp[$v['eva_id']][] = $v;
		$res = [];
		foreach($tmp as $v) {
			shuffle($v);
			$count = ceil( 20 / count($tmp) );
			$res = array_merge($res, array_slice($v, 0, $count));
		}

[一生小白]

大佬忽略了eid相同数超过两个的情况

$data = array(
    array(
        "eid" => "2","name" => "A1"
    ),
    array(
        "eid" => "2","name" => "A2"
    ),
    array(
        "eid" => "2","name" => "A3"
    ),
    array(
        "eid" => "8","name" => "B1"
    ),
    array(
        "eid" => "8","name" => "B2"
    ),
    array(
        "eid" => "5","name" => "C1"
    ),
    array(
        "eid" => "5","name" => "C2"
    )
);
foreach($data as $v) $tmp[$v['eid']][] = $v;
$res = [];
foreach($tmp as $v) {
    shuffle($v);
    $count = ceil(log(count($v)));
    if($count >1) $count = $count-1;
    $res = array_merge($res, array_slice($v, 0,$count));
}