How to check if duplicate values of some indexes exist in multi dimensional array or not?

Question

My problem is i have a multidimensional array posting from form to php, now i want to checking if duplicate values of some indexes exist in multi dimensional array or not? e.g:

$data=Array
(
    0 => Array
    (
        uid => '100',
        name => 'Sandra Shush',
        type => 'abc'
    ),
    1 => Array
    (
        uid  => '101',
        name => 'Sandra Shushtext',
        type => 'xyz'
    ),
    2 => Array
    (
        uid => '100',
        name => 'Sandra Shush',
        type => 'abc'
    )
);

here name and type of index 1 and 2 are same, so how can i check it?

I am familiar with

$key = array_search('abc', array_column($data, 'type'));

but it is for duplication of single column value in multi rows, in my situation if multi column of same rows same with multi column of any other row then record will be consider as duplicate.

Any help should be appreciated, Thanks in advance.

Mihai Matei · Accepted Answer · 2017-01-25 08:32:59Z

1

You can try using array_reduce by creating a key using your desired item keys:

$result = array_reduce($data, function ($carry, $item) {

    $key = $item['uid'] . $item['type'];

    $item['is_duplicate'] = isset($carry[$key]);

    if ($item['is_duplicate']) {
        $carry[] = $item;
    } else {
        $carry[$key] = $item;
    }

    return $carry;

}, []);

var_dump($result);

answered Jan 25, 2017 at 8:32

Mihai Matei

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Comments

malutki5200 · Accepted Answer · 2017-01-25 08:36:00Z

The easiest way, well at least the one I would use is to encode your arrays into md5 (or any other kind) string and compare those values.
I think it is the most efficient in your case.

Example:

<?php

function arrayToString($array) {
    $str = ''; 

    if ( !is_array($array) ) 
        return $str; 

    foreach ( $array as $key => $val ) {
        $str .= $key . ':' . $val; 
    }

    return $str; 
}

$data=Array
(
    0 => Array
    (
        'uid' => '100',
        'name' => 'Sandra Shush',
        'type' => 'abc'
    ),
    1 => Array
    (
        'uid'  => '100',
        'name' => 'Sandra Shush',
        'type' => 'xyz'
    ),
    2 => Array
    (
        'uid' => '100',
        'name' => 'Sandra Shush',
        'type' => 'abc'
    )
);

$temp = array(); 
foreach ( $data as $d ) {
    array_push($temp, md5(arrayToString($d))); 
}

$unique = array_unique($temp); 

var_dump($unique); // prints unique array

cb0 · Accepted Answer · 2017-01-25 08:37:37Z

This is a very fast designed approach and will find duplicates. Note that duplicates are elements which have the same value for the same key. So if any of uid, name or type match, they will be treated as duplicates. Therefore I adjust the third array element, because all elements in your array share the same values.

$data = [
    ....
    2 =>
        [
            'uid'  => '200',
            'name' => 'Mandra Shush',
            'type' => 'abcx'
        ]
];

$duplicates      = [];
$valuesToCompare = ["uid", "name", "type"];

function equals($value, $toCompare, $keysToCompare)
{
    foreach ($keysToCompare as $compareKey) {
        if ($value[$compareKey] === $toCompare[$compareKey]) {
            return true;
        }
    }

    return false;
}

foreach ($data as $index => $element) {
    foreach ($data as $indexInner => $elementToCompare) {
        if ($index !== $indexInner) {
            if (equals($element, $elementToCompare, $valuesToCompare)) {
                $duplicates[] = [$index => $indexInner];
            }
        }
    }
}

var_dump($duplicates);

This will output the following, which indicates we found 2 duplicates. Where element 0 is duplicate of 1, and 1 is duplicate of 0.

array (size=2)
  0 => 
    array (size=1)
      0 => int 1
  1 => 
    array (size=1)
      1 => int 0

Imran Qamer · Accepted Answer · 2017-01-27 09:14:33Z

0

I achieved above scenario like this:

Dont know which one is best mine or other's who posted answers.

foreach($data as $key => $row)
{
    $combinedarr[] = array("name"=>$row["name"],"type"=>$row["type"]);
}
//chck if same facilitiy is being visit on same date twice
$countcomb = count($combinedarr);
$uniquearr = array_unique($combinedarr, SORT_REGULAR);
if($countcomb==count($uniquearr)){
}else{
    //yes duplicate exists
};

Thanks again for those who answered.

answered Jan 27, 2017 at 9:14

Imran Qamer

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