find all duplicates values in multi dimensional array php - php

Question

I have a array as following
array(
0 => array('email' => 'abc#abc.com','name'=>'abc'),
1 => array('email' => 'xyz#abc.com','name'=>'xyz'),
2 => array('email' => 'uvw#abc.com','name'=>'uvw'),
3 => array('email' => 'abc#abc.com','name'=>'str'),
)
I want to filter out records on email address and get records having same email address. For example from above example I want
array(
0 => array(
array(
0 => array('email' => 'abc#abc.com','name'=>'abc'),
1 => array('email' => 'abc#abc.com','name'=>'str'),
)
)
My code is
$tmpArray = array();
$duplicateRecords = array();
if (empty($data)) {
return false;
}
foreach ($data as $key => $value) {
if (in_array($value['Email'], $tmpArray)) {
$duplicateRecords[] = $value;
}
$tmpArray[] = $value['Email'];
}
echo '<pre>';print_r($duplicateRecords);die;
But this piece of code only returns the record's once existance, which is of second time. I know when It is traversing first time it isn't having email to compare. Is there any way to get existence of record as many times as it is in array.

Answer 1

// get count of each email
$counters = array_count_values(array_column($data, 'email'));
// collect email with counter > 1
$result = [];
foreach ($data as $item) {
if ($counters[$item['email']] > 1) {
$result[] = $item;
}
}

Answer 2

This one should work for you:
foreach($array as $key => $value) {
foreach ($array as $k => $v) {
if ($key < $k && $value['email'] == $v['email']) {
$result[] = array(
$value,
$v
);
}
}
}
PHPFiddle Link: http://phpfiddle.org/main/code/8trq-k2zc
Please note: this would only find you the conflicting pairs. For example:
$array = array(
array(
'email' => 'abc#abc.com',
'name' => 'abc'
),
array(
'email' => 'abc#abc.com',
'name' => 'def'
),
array(
'email' => 'abc#abc.com',
'name' => 'ghi'
)
);
Would result in:
Array
(
[0] => Array
(
[0] => Array
(
[email] => abc#abc.com
[name] => abc
)
[1] => Array
(
[email] => abc#abc.com
[name] => def
)
)
[1] => Array
(
[0] => Array
(
[email] => abc#abc.com
[name] => abc
)
[1] => Array
(
[email] => abc#abc.com
[name] => ghi
)
)
[2] => Array
(
[0] => Array
(
[email] => abc#abc.com
[name] => def
)
[1] => Array
(
[email] => abc#abc.com
[name] => ghi
)
)
)
So abc conflicts with def, abc conflicts with ghi, and def conflicts with ghi.

Answer 3

This is a 'two pass' solution. The code is commented.
PHP 5.3.18
<?php // https://stackoverflow.com/questions/26548634/find-all-duplicates-values-in-multi-dimensional-array-php
$data = array(
0 => array('email' => 'abc#abc.com','name'=>'abc'),
1 => array('email' => 'xyz#abc.com','name'=>'xyz'),
2 => array('email' => 'uvw#abc.com','name'=>'uvw'),
3 => array('email' => 'abc#abc.com','name'=>'str'),
);
// two passes required
// first pass: count of emails
$emailCounts = array();
foreach($data as $emailEntry) {
if (isset($emailCounts[$emailEntry['email']])) {
$emailCounts[$emailEntry['email']] += 1;
}
else {
$emailCounts[$emailEntry['email']] = 1;
}
}
// second pass: extract duplicate emails (count > 1)
$duplicateEmails = array();
foreach($data as $emailEntry) {
if ($emailCounts[$emailEntry['email']] > 1) {
$duplicateEmails[] = $emailEntry;
}
}
// show output...
var_dump($emailCounts);
var_dump($duplicateEmails);
Actual output:
array
'abc#abc.com' => int 2
'xyz#abc.com' => int 1
'uvw#abc.com' => int 1
array
0 =>
array
'email' => string 'abc#abc.com' (length=11)
'name' => string 'abc' (length=3)
1 =>
array
'email' => string 'abc#abc.com' (length=11)
'name' => string 'str' (length=3)

Answer 4

Here is the code for you
>$mainarray=array(
0 => array('email' => 'abc#abc.com','name'=>'abc'),
1 => array('email' => 'xyz#abc.com','name'=>'xyz'),
2 => array('email' => 'uvw#abc.com','name'=>'uvw'),
3 => array('email' => 'abc#abc.com','name'=>'str'),
);
foreach($mainarray as $single){
$emailarray[]=$single['email'];
}
foreach(array_count_values($emailarray) as $val => $c)
if($c > 1) $dups[] = $val;
foreach($mainarray as $single){
if(in_array($single['email'], $dups)){
$result[]=$single;
}
}
echo '<pre>';print_r($result);