如何从PHP多维数组中删除重复值?
示例数组:
Array
(
[0] => Array
(
[0] => abc
[1] => def
)
[1] => Array
(
[0] => ghi
[1] => jkl
)
[2] => Array
(
[0] => mno
[1] => pql
)
[3] => Array
(
[0] => abc
[1] => def
)
[4] => Array
(
[0] => ghi
[1] => jkl
)
[5] => Array
(
[0] => mno
[1] => pql
)
)
当前回答
序列化和惟一的替代方案
$test = [ ['abc','def'], ['ghi','jkl'], ['mno','pql'], ['abc','def'], ['ghi','jkl'], ['mno','pql'], ]; $result = array_reduce( $test, function($carry,$item){ if(!in_array($item,$carry)) { array_push($carry,$item); } return $carry; }, [] ); var_dump($result); /* php unique.php array(3) { [0] => array(2) { [0] => string(3) "abc" [1] => string(3) "def" } [1] => array(2) { [0] => string(3) "ghi" [1] => string(3) "jkl" } [2] => array(2) { [0] => string(3) "mno" [1] => string(3) "pql" } } */
其他回答
如果您需要消除特定键上的重复项，例如mysqli id，这里有一个简单的函数
function search_array_compact($data,$key){
$compact = [];
foreach($data as $row){
if(!in_array($row[$key],$compact)){
$compact[] = $row;
}
}
return $compact;
}
加分 您可以传递一个键数组并添加一个外部foreach，但每增加一个键将慢2倍。
对此，array_unique()文档上的用户注释提供了许多解决方案。这是其中之一:
kenrbnsn at rbnsn dot com 27-Sep-2005 12:09 Yet another Array_Unique for multi-demensioned arrays. I've only tested this on two-demensioned arrays, but it could probably be generalized for more, or made to use recursion. This function uses the serialize, array_unique, and unserialize functions to do the work. function multi_unique($array) { foreach ($array as $k=>$na) $new[$k] = serialize($na); $uniq = array_unique($new); foreach($uniq as $k=>$ser) $new1[$k] = unserialize($ser); return ($new1); }
这来自http://ca3.php.net/manual/en/function.array-unique.php#57202。
我也遇到过类似的问题，但我找到了一个100%有效的解决方案。
<?php
function super_unique($array,$key)
{
$temp_array = [];
foreach ($array as &$v) {
if (!isset($temp_array[$v[$key]]))
$temp_array[$v[$key]] =& $v;
}
$array = array_values($temp_array);
return $array;
}
$arr="";
$arr[0]['id']=0;
$arr[0]['titel']="ABC";
$arr[1]['id']=1;
$arr[1]['titel']="DEF";
$arr[2]['id']=2;
$arr[2]['titel']="ABC";
$arr[3]['id']=3;
$arr[3]['titel']="XYZ";
echo "<pre>";
print_r($arr);
echo "unique*********************<br/>";
print_r(super_unique($arr,'titel'));
?>
对于长度不受限制的(n)维数组，尝试此解决方案 比如这个数组
$arr= [
0 => [0=>"a" , 1=>"b" , 2=>"c" ] ,
1 => [0=>"x" , 1=>"b" , 2=>"a", 3=>"p"],
2=> [
[
0=>"y" ,
1=>"b" ,
2=> [0=>"x" , 1=>"m" , 2=>"a"]
],
1=>"z" ,
2=>"v"
]
];
这就是答案
$ar2=[];
$ar3=[];
function test($arr){
global $ar2,$ar3;
if(is_array($arr)){
return array_map("test",$arr);
}
if(!isset($ar2[$arr])){
$ar2[$arr]=1;
$ar3[]=$arr;
}
}
array_map("test",$arr);
print_r($ar3);
Array
(
[0] => Array
(
[id] => 1
[name] => john
)
[1] => Array
(
[id] => 2
[name] => smith
)
[2] => Array
(
[id] => 3
[name] => john
)
[3] => Array
(
[id] => 4
[name] => robert
)
)
$temp = array_unique(array_column($array, 'name'));
$unique_arr = array_intersect_key($array, $temp);
这将从数组中删除重复的名称。按键唯一
