Array comparison and re-order in PHP - php

Question

Let's say I Have two arrays.
$arr1 = ['A','B','C','D'];
$arr2 = ['C','D'];
now compare two arrays.if there is no match for value of $arr1 in $arr2 then index is left empty.
for the above arrays output should be:
$arr3 = ['','','C','D']
I tried array_search() function.But couldn't achieve desired output.
Any possible solutions?

Answer 1

You can use foreach with in_array and array_push like:
$arr1 = ['A','B','C','D'];
$arr2 = ['C','D'];
$arr3 = [];
foreach($arr1 as $value){
$arr3[] = (in_array($value, $arr2)) ? $value : '';
}
print_r($arr3);
/*
Result
Array
(
[0] =>
[1] =>
[2] => C
[3] => D
) */
Foreach the first array then test with in_array if exist, if true push into array 3 else push empty value

Answer 2

You can use the following function. In the following code, the function search_in_array return true and false based on the searching within the 2nd array. So you can push the empty or searched value in final array.
<?php
$arr1 = array('A','B','C','D');
$arr2 = array('C','D');
$arr3 = array();
function search_in_array ($value, $array)
{
for ($i=0; $i<count($array); $i++)
{
if ($value == $array[$i])
{
return true;
}
}
return false;
}
for ($i=0; $i<count($arr1); $i++)
{
$value = $arr1[$i];
$result = search_in_array ($value, $arr2);
if ($result)
{
array_push ($arr3, $value);
}
else
{
array_push ($arr3, '');
}
}
print_array($arr3);
?>