从一个数组中删除重复的数组

Question

这是我正在处理的数组示例：

Array
(
[0] => Array
    (
        [id] => 1331
        [shortname] => MCS-115-113C
        [userid] => 663
        [email] => [e-mail]
        [username] => FOOBARBAZ
        [nombrecompleto] => asdfasdf
        [lastlogin] => 1367501486
    )
[1] => Array
    (
        [id] => 1331
        [shortname] => MAFA-EOOF
        [userid] => 323
        [email] => [e-mail]
        [username] => FOOBARBAZ
        [nombrecompleto] => asdfasdf
        [lastlogin] => 136732186
    )
[2] => Array
    (
        [id] => 1331
        [shortname] => MKT-FOOBAR
        [userid] => 434
        [email] => [e-mail]
        [username] => adsfasdf
        [nombrecompleto] => asdfasdf
        [lastlogin] => 1367234486
    )

在我的情况下，我想比较数组中的username元素并删除重复项。

因此，在这种情况下，我只会返回两个元素，用户名FOOBARBAZ和adsfasdf:

Array
(
[0] => Array
    (
        [id] => 1331
        [shortname] => MAFA-EOOF
        [userid] => 323
        [email] => [e-mail]
        [username] => FOOBARBAZ
        [nombrecompleto] => asdfasdf
        [lastlogin] => 136732186
    )
[1] => Array
    (
        [id] => 1331
        [shortname] => MKT-FOOBAR
        [userid] => 434
        [email] => [e-mail]
        [username] => adsfasdf
        [nombrecompleto] => asdfasdf
        [lastlogin] => 1367234486
    )

如何在PHP中完成这个任务？

- sergserg

---

你看过array_unique()了吗？ - Bailey Parker

如果这个数组来自一个查询，我建议在你的SQL中修复它，以减少SQL和PHP之间的流量。 - Fabrício Matté

Answer 1

使用array_unique()函数可以轻松实现（由于是内部处理，所以速度很快）。然而，默认情况下该函数会将所有内容转换为字符串，因此您需要传递SORT_REGULAR常量。（演示）

<?php
$data = array(
    array(
        'id' => 0,
        'title' => 'Abc'
    ),
    array(
        'id' => 2,
        'title' => 'Def',
        'content' => 'Stackoverflow!'
    ),
    array(
        'id' => 0,
        'title' => 'Abc'
    )
);

var_dump(array_unique($data, SORT_REGULAR));

- Bailey Parker

Answer 2

试试这个：

<?php

$test=array
(
0 => array
    (
        'id' => '1331',
        'shortname' => 'MCS-115-113C',
        'userid' => '663',
        'email' => '[e-mail]',
        'username' => 'FOOBARBAZ',
        'nombrecompleto' => 'asdfasdf',
        'lastlogin' => '1367501486',
    ),
1 => array
    (
        'id' => '1331',
        'shortname' => 'MAFA-EOOF',
        'userid' => '323',
        'email' => '[e-mail]',
        'username' => 'FOOBARBAZ',
        'nombrecompleto' => 'asdfasdf',
        'lastlogin' => '136732186'
    ),
2 => array
    (
        'id' => '1331',
        'shortname' => 'MKT-FOOBAR',
        'userid' => '434',
        'email' => '[e-mail]',
        'username' => 'adsfasdf',
        'nombrecompleto' => 'asdfasdf',
        'lastlogin' => '1367234486'
    )
);

$userdupe=array();

foreach ($test as $index=>$t) {
    if (isset($userdupe[$t["username"]])) {
        unset($test[$index]);
        continue;
    }
    $userdupe[$t["username"]]=true;
}

print_r($test);
?>

- Dave Chen

Answer 3

您可以使用以下代码：

$result = array_unique($data,3);

- Alireza Salehi

---

欢迎来到Stack Overflow！感谢您提供这段代码片段，它可能会在短期内提供一些有限的帮助。通过展示为什么这是一个好的解决方案，适当的解释可以极大地提高其长期价值，并使其对其他类似问题的未来读者更加有用。请编辑您的答案，添加一些说明，包括您做出的假设。 - Toby Speight

Answer 4

/* here is your array */
$array = array(
    0 => array(
            'id' => '1331',
            'shortname' => 'MCS-115-113C',
            'userid' => '663',
            'email' => '[e-mail]',
            'username' => 'FOOBARBAZ',
            'nombrecompleto' => 'asdfasdf',
            'lastlogin' => '1367501486',
    ),
    1 => array(
            'id' => '1331',
            'shortname' => 'MAFA-EOOF',
            'userid' => '323',
            'email' => '[e-mail]',
            'username' => 'FOOBARBAZ',
            'nombrecompleto' => 'asdfasdf',
            'lastlogin' => '136732186'
    ),
    2 => array(
            'id' => '1331',
            'shortname' => 'MKT-FOOBAR',
            'userid' => '434',
            'email' => '[e-mail]',
            'username' => 'adsfasdf',
            'nombrecompleto' => 'asdfasdf',
            'lastlogin' => '1367234486'
    )
);

/* initializing an array to store usernames to compare */
$userNames = array();
/* looping through array */
foreach($array as $key=>$value){
    if(!empty($userNames) && in_array($value['username'],$userNames)) unset($array[$key]);  //unset from $array if username already exists
    $userNames[] = $value['username'];  // creating username array to compare with main array values
}

/* print updated array */
echo "<pre>";print_r($array);echo "</pre>";

- Ankit Gupta

Answer 5

请使用以下代码：

$array = [
    ["a"],
    ["a"],
    ["b"],
];

$isContainDupes = count($array) !== count(array_unique($array, SORT_REGULAR));
var_dump($isContainDupes); // true

- ziishaned