Removing subarrays that share a key-value pair with another multidimensional array - php

Question

I have 2 arrays as below. I want to remove data from array2 if array1 has the stu_id. final array should be like result_array.
$array1 = Array
(
[0] => Array
(
[stu_id] => 1
[name] => mr.a
)
[1] => Array
(
[stu_id] => 3
[name] => mr.b
)
)
$array2 = Array
(
[0] => Array
(
[id] => 1
[stu_id] => 1
[data] => abc
)
[1] => Array
(
[id] => 2
[stu_id] => 2
[data] => xyz
)
[3] => Array
(
[id] => 3
[stu_id] => 3
[data] => aaa
)
)
$result_array = Array
(
[0] => Array
(
[id] => 2
[stu_id] => 2
[data] => xyz
)
)
I tried array_diff, $result_array = array_diff($array2, $array1); but it's not working.
Please help me to do this.

Answer 1

Temporarily assign keys using array_column() with stud_id (NULL retains the full subarray data), then use array_diff_key() to filter, and array_values() to reset the keys:
Code: (Demo)
$array1=[
['stu_id'=>1,'name'=>'mr.a'],
['stu_id'=>3,'name'=>'mr.b']
];
$array2=[
['id'=>1,'stu_id'=>1,'data'=>'abc'],
['id'=>2,'stu_id'=>2,'data'=>'xyz'],
['id'=>3,'stu_id'=>3,'data'=>'aaa']
];
//var_export(array_column($array1,NULL,'stu_id'));
//var_export(array_column($array2,NULL,'stu_id'));
var_export(array_values(array_diff_key(array_column($array2,NULL,'stu_id'),array_column($array1,NULL,'stu_id'))));
Output:
array (
0 =>
array (
'id' => 2,
'stu_id' => 2,
'data' => 'xyz',
),
)
If you'd like to use a foreach loop structure, generate a filtering array of stu_id's from $array1 and write a conditional check on each iteration of $array2. This method doesn't not modify the original arrays, so they can be reused "down script".
Code:
$stu_ids=array_column($array1,'stu_id');
foreach($array2 as $row){
if(!in_array($row['stu_id'],$stu_ids)){
$result[]=$row; // auto-index the qualifying subarrays
}
}
var_export($result);
// same result as above method

Answer 2

foreach($array1 as $data1){
foreach($array2 as $k => $data2){
if($data2["stu_id"] == $data1["stu_id"]){
unset($array2[$k]);
break;
}
}
}
$result_array = $array2;