Multi-dimensional array, remove array where key and value match another array - php

Question

I want to remove duplicates where either measurement or altunit matches another array, but ignoring if they're blank.
Array
(
[0] => Array
(
[id] => 2
[altunit] => %
[measurement] =>
)
[1] => Array
(
[id] => 3
[altunit] =>
[measurement] => 6
)
[2] => Array
(
[id] => 4
[altunit] => %
[measurement] =>
)
[3] => Array
(
[id] => 5
[altunit] =>
[measurement] => 6
)
[4] => Array
(
[id] => 6
[altunit] =>
[measurement] => 6
)
)
Becomes
Array
(
[0] => Array
(
[id] => 2
[altunit] => %
[measurement] =>
)
[1] => Array
(
[id] => 3
[altunit] =>
[measurement] => 6
)
)
Best I can come up with is:
$test = array ( 0 => array ( 'id' => '2', 'altunit' => '%', 'measurement' => NULL, ), 1 => array ( 'id' => '3', 'altunit' => NULL, 'measurement' => '6', ), 2 => array ( 'id' => '4', 'altunit' => NULL, 'measurement' => '6', ), 3 => array ( 'id' => '5', 'altunit' => NULL, 'measurement' => '6', ), 4 => array ( 'id' => '6', 'altunit' => NULL, 'measurement' => '6', ), );
$num = [];
foreach($test as $k => $v) $num[] = $v['measurement'];
But this only works for measurement, and removes the id and altunit keys.

Answer 1

Humm,
Make an array of 'knowed value' for measurement and altunit and then check it it exist on the rest of the values.
something like:
$knowed_altunit=array();
$knowed_measurement=array();
foreach($test as $k=>$v){
if(in_array($v['altunit'],$knowed_altunit)
|| in_array($v['mesurement'],$knowed_measurement)){
//if the value of altunit or measurement is already knowed then remove the entry from the array,
unset($test[$k]);
}else{
//if it never been seen, add it so further entry can be checked agaisnt the knowed value
$knowed_altunit[]=$v['altunit'];
$knowed_measurement[]=$v['mesurement'];
}
}
Sorry if any typo but thins might help you wrap your head around the solution to your problem.

Answer 2

You can try this code:
<?php
/* before you need to check that $test variable is declarated and have all items to check */
$values_altunit = array();
$values_measurement = array();
$result = array();
foreach($test as $key => $value) {
/* check if exist altunit and measurement values in blacklist arrays */
if (!in_array($value['altunit'], $values_altunit) && !in_array($value['measurement'], $values_measurement)) {
/* if not exist, add the item to $result array */
$result[$key] = $value;
/* and add altunit and measurement values to blacklist arrays */
$values_altunit[] = $value['altunit'];
$values_measurement[] = $value['measurement'];
}
}
/* print result items */
var_dump($result);
?>

Answer 3

This is a short code that can give the result for unique measurements
<?php
$arr = array(
"0"=> array (
"id" => 2,
"altunit" => "%",
"measurement" => "",
),
"1"=> array (
"id" => 3,
"altunit" => "",
"measurement" => 6,
),
"2"=> array (
"id" => 4,
"altunit" => "%",
"measurement" => "",
),
"3"=> array (
"id" => 5,
"altunit" => "",
"measurement" => 6,
),
"4"=> array (
"id" => 6,
"altunit" => "",
"measurement" => 6,
)
);
$unique_measure = $new_array = array();
foreach($arr as $sup_key => $sup_val){
foreach($sup_val as $sub_key => $sub_val){
if(!in_array($sup_val['measurement'], $unique_measure)){
array_push($unique_measure, $sup_val['measurement']);
array_push($new_array,$sup_val);
}
}
}
print_r($new_array);
?>
Output :
Array
(
[0] => Array
(
[id] => 2
[altunit] => %
[measurement] =>
)
[1] => Array
(
[id] => 3
[altunit] =>
[measurement] => 6
)
)
try this code. it may do the trick.
One More approach to your problems solution can be removing that particular key from the main array using unset(your_array_key) will do the trick in the same code.

Answer 4

Try, this may help you
function remove_dup($array, $keys )
{
$out = array();
foreach($array as $sub)
{
if(empty($out))
{
$out[] = $sub;
continue;
}
foreach($keys as $key)
{
if($flag=in_array( $sub[$key],array_map(function($e) use($key){ return $e[$key];}, $out)) )
break;
}
if(!$flag)
$out[] = $sub;
}
return $out;
}
// Usage
print_r( remove_dup($array, array('altunit','measurement') ) );
Test
[akshay#localhost tmp]$ cat test.php
<?php
function remove_dup($array, $keys )
{
$out = array();
foreach($array as $sub)
{
if(empty($out))
{
$out[] = $sub;
continue;
}
foreach($keys as $key)
{
if($flag=in_array( $sub[$key],array_map(function($e) use($key){ return $e[$key];}, $out)) )
break;
}
if(!$flag)
$out[] = $sub;
}
return $out;
}
$array = array(
"0"=> array (
"id" => 2,
"altunit" => "%",
"measurement" => "",
),
"1"=> array (
"id" => 3,
"altunit" => "",
"measurement" => 6,
),
"2"=> array (
"id" => 4,
"altunit" => "%",
"measurement" => "",
),
"3"=> array (
"id" => 5,
"altunit" => "",
"measurement" => 4,
),
"4"=> array (
"id" => 6,
"altunit" => "",
"measurement" => 6,
)
);
print_r( remove_dup($array, array('altunit','measurement') ) );
?>
Output
[akshay#localhost tmp]$ php test.php
Array
(
[0] => Array
(
[id] => 2
[altunit] => %
[measurement] =>
)
[1] => Array
(
[id] => 3
[altunit] =>
[measurement] => 6
)
)

Answer 5

What you really want is a set, not an array. So if you can't fix the way you're building the array in the first place (my guess is this came from an SQL query, which would be a lot less code to rectify) you have two options for creating mapped sets in PHP.
You could use SplObjectStorage
You could use an Array with the key as a serialized representation of the set
The first approach would look something like this...
$set = new SplObjectStorage();
$arr = [
0 => [
'id' => '2',
'altunit' => '%',
'measurement' => NULL,
],
1 => [
'id' => '3',
'altunit' => NULL,
'measurement' => '6',
],
2 => [
'id' => '4',
'altunit' => NULL,
'measurement' => '6',
],
3 => [
'id' => '5',
'altunit' => NULL,
'measurement' => '6',
],
4 => [
'id' => '6',
'altunit' => NULL,
'measurement' => '6',
],
];
foreach($arr as $part) {
if (isset($part['altunit'])) { // ignore if blank
$key = (object) $part;
$set->attach($key); // attach the set
}
}
// Now you have...
foreach($set as $value) {
var_dump($value);
}
This would give you...
object(stdClass)#2 (3) {
["id"]=>
string(1) "2"
["altunit"]=>
string(1) "%"
["measurement"]=>
NULL
}
The second approach, using an array, where the array key represents a serialized version of the set would look something like this...
$set = [];
$arr = [
0 => [
'id' => '2',
'altunit' => '%',
'measurement' => NULL,
],
1 => [
'id' => '3',
'altunit' => NULL,
'measurement' => '6',
],
2 => [
'id' => '4',
'altunit' => NULL,
'measurement' => '6',
],
3 => [
'id' => '5',
'altunit' => NULL,
'measurement' => '6',
],
4 => [
'id' => '6',
'altunit' => NULL,
'measurement' => '6',
],
];
foreach($arr as $part) {
if (isset($part['altunit'])) { // ignore if blank
$key = "{$part['altunit']}\0{$part['measurement']}";
$set[$key] = $part; // attach the set
}
}
// Now you have...
foreach($set as $value) {
var_dump($value);
}
And that would give you...
array(3) {
["id"]=>
string(1) "2"
["altunit"]=>
string(1) "%"
["measurement"]=>
NULL
}
N.B
But, if this is a result set from an SQL query it's quite possible you could just more effectively eliminate the de-duplication process entirely by modifying the query to use WHERE NOT NULL and GROUP BY clauses instead.

Answer 6

You can try this also
<?php
$keys = array_map(function ($i) { return $i; }, $array);
$dumparr = array_combine($keys, $array);
$result = array_values($deduped);
print_r($result);
?>