How can I map two arrays based on specific indexes? - php

Question

Array1 ( [0] => [1] => [2] => 3 [3] => [4] => 5 [5] => [6] => )
Array2 ( [0] => URD [1] => ISL )
I want to map $array2 values to $array1 indexes (those having values 3 and 5) and I want get an array like this:
Array ( [0] => [1] => [2] => URD [3] => [4] => ISL [5] => [6] => )
I have tried the following:
$newArray = array_values(array_filter(array_merge($array1,$array2)));
but the actual result is:
Array([0] => 3[1] => 5[2] => URD[3] => ISL)
The expected result should be:
Array ( [0] => [1] => [2] => URD [3] => [4] => ISL [5] => [6] => )

Answer 1

Code
Try the following:
<?php
$array1 = ["", "", "3", "", "5", "", ""];
$array2 = ["URD", "ISL"];
foreach($array1 as $id => $a1){
//for each item in array 1
if($a1){
//if the array 1 item has a value
$array1[$id] = array_shift($array2);
//replace it with an item from array 2
}
if(empty($array2)){
//if there are no more values left to share in array 2, stop
break;
}
}
var_dump($array1);
Output
array(7) {
[0]=>
string(0) ""
[1]=>
string(0) ""
[2]=>
string(3) "URD"
[3]=>
string(0) ""
[4]=>
string(3) "ISL"
[5]=>
string(0) ""
[6]=>
string(0) ""
}
Caveats
The method assumes that there will be values in both array 1 and array 2.
Once the values in array 2 have been split out and array 2 is empty, array 1 items with set values will no longer be affected.
The method does not care what the value set in array 1 is, just that there is a value.
Further reading
foreach()
array_shift()
Codepen
https://3v4l.org/RDQY6

Answer 2

This solution works and simple to understands as OPS requested...
<?
$array1 = ["", "", "3", "", "5", "", ""];
$array2 = ["URD", "ISL"];
$i =0;
foreach($array1 as $keys=>$values) {
if($values == 3 || $values ==5) {
if(isset($array2[$i])){
$array1[$keys] = $array2[$i];
$i++;
}else { break; }
}
}
print_R($array1);
?>
it will replace the array2 values from array 1 values wherever 5 & 3 will come and which is independent of their sorting order.
example
$array1 = ["5", "", "3", "", "", "", ""]; will be converted into
$array1 = ["URD", "" ,"ISL","","",""];
if you want it in order like 3 should always come first then first sort array1 then use my code...
if you want 3 should be replace by URD and 5 should be replace by ISL
then you if codition will be different

Answer 3

Just another way to do it... (untested, but it should work)
<?php
$a = array ( 0 => '', 1 => '', 2 => 3, 3 => '', 4 => 5, 5 => '', 6 => '' );
$b = array ( 0 => 'URD', 1 => 'ISL' );
$c = array_replace ( $a, array_combine ( array_keys ( array_filter ( $a ) ), $b ) );
print_r ( $c );
?>