Get array object data from exploded array fields in foreach loop - arrays

Question

I'm trying to extract data from our JSON data based on given output fields, but I'm not getting a good result.
e.g.
Given fields that I want:
Array
(
[0] => id
[1] => name
[2] => email
[3] => optin_email
)
Those fields exist in my datastring, I want to export those to a CSV.
I can do this, hardcoded
foreach ($jsonString as $value) {
$row = [
$value->id,
$value->name,
$value->email,
$value->phone
];
print_r($row);
}
The above will give me the list/file I need. BUT, I want to make that dynamic based on the data in the array, so, fo rexample, when this is the Array:
Array
(
[0] => id
[1] => name
)
This should be my output:
foreach ($jsonString as $value) {
$row = [
$value->id,
$value->name
];
print_r($row);
}
So I need to dynamicly create the
$value->{var}
I have been trying forever, but I am not seeing it straight anymore.
Tried this:
$rowFields = '';
foreach ($export_datafields AS $v) {
$rowFields .= '$value->' . $v . ',';
}
$trimmed_row_fields = rtrim($rowFields, ',');
foreach ($jsonString as $value) {
$row = $trimmed_row_fields;
print_r($row);
}
And several variations of that:
foreach ($jsonString as $value) {
$row = [$trimmed_row_fields];
print_r($row);
}
Question is: how can I get
$value->VAR
as a valid array key when I only know the VAR name and need the prefixed $value-> object.

Answer 1

I ended up using the following code which works for me. If anybody still has the answer to my original question, please shoot. Always good to know it all.
header("Content-type: application/csv");
header("Content-Disposition: attachment; filename=$csvFileName");
header("Pragma: no-cache");
header("Expires: 0");
$new_row = implode(",", $export_datafields) . "\n";
foreach ($jsonString as $value) {
foreach ($export_datafields AS $v) {
$new_row .= $value->$v . ',';
}
$new_row = substr($new_row, 0, -1);
$new_row .= "\n";
}
echo $new_row;