如果两个值匹配，则从php中的多维关联数组中删除重复项

Question

我有一个如下结构的多维数组，我想从中删除重复项。例如，如果两个["city"]的["amount"]相同，但["time"]相同或不同，那么我认为这是重复项，并想从数组中删除此节点。

在下面的示例中，我想从数组中完全删除节点0，因为城市和数量与节点1相同。他们都是布里斯托尔（英国布里斯托尔）和373，尽管时间是17:15和17:16。

如果时间与本例不同，那么我会删除后面的时间。

array(8) {
  [0]=>
  array(3) {
    ["time"]=>
    string(5) "17:16"
    ["city"]=>
    string(33) "Bristol (Bristol, United Kingdom)"
    ["amount"]=>
    int(373)
  }
  [1]=>
  array(3) {
    ["time"]=>
    string(5) "17:15"
    ["city"]=>
    string(33) "Bristol (Bristol, United Kingdom)"
    ["amount"]=>
    int(373)
  }
  [2]=>
  array(3) {
    ["time"]=>
    string(5) "17:16"
    ["city"]=>
    string(37) "Wednesbury (Sandwell, United Kingdom)"
    ["amount"]=>
    int(699)
  }
  [3]=>
  array(3) {
    ["time"]=>
    string(5) "17:16"
    ["city"]=>
    string(45) "Wolverhampton (Wolverhampton, United Kingdom)"
    ["amount"]=>
    int(412)
  }
  [4]=>
  array(3) {
    ["time"]=>
    string(5) "17:15"
    ["city"]=>
    string(33) "Swansea (Swansea, United Kingdom)"
    ["amount"]=>
    int(249)
  }
  [5]=>
  array(3) {
    ["time"]=>
    string(5) "17:16"
    ["city"]=>
    string(39) "Watford (Hertfordshire, United Kingdom)"
    ["amount"]=>
    int(229)
  }
  [6]=>
  array(3) {
    ["time"]=>
    string(5) "17:14"
    ["city"]=>
    string(39) "Nottingham (Nottingham, United Kingdom)"
    ["amount"]=>
    int(139)
  }
  [7]=>
  array(3) {
    ["time"]=>
    string(5) "17:13"
    ["city"]=>
    string(31) "Dartford (Kent, United Kingdom)"
    ["amount"]=>
    int(103)
  }
}

Answer 1

试试这个：

$result = array();
foreach ($array as $place) {
    if (!array_key_exists($place['time'], $result)) {
        $result[$place['time']] = $place;
    }
}

Answer 2

<?php
$data = array(
    array(
        'time' => '17:16',
        'city' => 'Bristol',
        'amount' => 373,
    ),
    array(
        'time' => '18:16',
        'city' => 'Bristol',
        'amount' => 373,
    ),
    array(
        'time' => '18:16',
        'city' => 'Wednesbury',
        'amount' => 699,
    ),
    array(
        'time' => '19:16',
        'city' => 'Wednesbury',
        'amount' => 699,
    ),
);
$tmp = array();
foreach ($data as $row) {
    $city   = $row['city'];
    $amount = $row['amount'];
    if (!isset($tmp[$city][$amount]) 
        || $tmp[$city][$amount]['time'] < $row['time']) {
        $tmp[$city][$amount] = $row;
    }
}
$data = array();
foreach ($tmp as $cities) {
    foreach ($cities as $city) {
        $data[] = $city;
    }
}
var_dump($data);

Answer 3

创建一个二维关联数组，其中一个维度是城市的键控，另一个是金额：

$assoc = array();
foreach ($data as $el) {
    $city = $el['city'];
    $amount = $el['amount'];
    if (isset($assoc[$city]) {
        $assoc[$city][$amount] = $el;
    } else {
        $assoc[$city] = array($amount => $el);
    }
}
// Now gather up all the elements back into a single array
$result = array();
foreach ($assoc as $cities)
    foreach ($cities as $city) {
        $result[] = $city;
    }
}