PHP replace Array values based on certain requirements - php

Question

I have an array as such:
$array = ["1","0","0","1","1"]
//replace with
$newArray = ["honda","toyota","mercedes","bmw","chevy"]
// only if the original array had a value of "1".
// for example this is my final desired output:
$newArray = ["honda","0","0","bmw","chevy"]
I want to change each value in a specific order IF and only if the array value is equal to "1".
For example the values, "honda", "toyota", "mercedes", "bmw", "chevy" should only replace the array values if the value is "1" otherwise do not replace it and they must be in the right position for example the first element in the array must only be changed to honda, not toyota or any of the other values.
I know I must iterate through the array and provide an if statement as such:
foreach($array as $val) {
if($val == 1){
//do something
} else {
return null;
}
}
Please guide me in the right direction and describe how to replace the values in order, so that toyota cannot replace the first array value only the second position.

Answer 1

You can so something like this - iterating over the array by reference and replacing when the value is 1 (string) and the value in the replace array exists:
foreach($array as $key => &$current) {
if($current === '1' && isset($replace[$key]))
$current = $replace[$key];
}
Output:
Array
(
[0] => honda
[1] => 0
[2] => 0
[3] => bmw
[4] => chevy
)
As per your comment, to output an imploded list of the cars that do have values, you can do something like this - filtering out all zero values and imploding with commas:
echo implode(
// delimiter
', ',
// callback - filter out anything that is "0"
array_filter($array, function($a) {
return $a != '0';
})
);

Answer 2

Currently, our if is asking if $val is true (or if it exists) while your numeric array's values are strings.
Try this:
$array = ["1","0","0","1","1"]
$newArray = ["honda","toyota","mercedes","bmw","chevy"]
foreach($array as $key => $val) {
if($val === '1'){ // if you only want honda
$array[$key] = $newArray[$key];
} else {
return null;
}
}

Answer 3

PHP Code
$array = array("1","0","0","1","1");
$newArray = array("honda","toyota","mercedes","bmw","chevy");
foreach($array as $key => $val) {
if($val === '1')
$array[$key] = $newArray[$key];
}
Would produce the answer you're looking for