PHP read JSON Array with unknown variable - php

Question

I have a Json Script with an Array inside and Array which looks like this shortened:
Array
(
[assets] => Array
(
[CGGD.AS] => Array
(
[shortName] => iShares Global Govt Bond Climat
[sector] =>
[industry] =>
[country] =>
[longBusinessSummary] =>
[currency] => USD
[marketCap] =>
[logo_url] =>
[Anlageklasse] => Anleihen
[Anmerkungen] => Staatsanleihen Welt
[Nachhaltigkeit] => 1
[Ist_Alternative] => 1
[weights] => 0.86563025602977
)
[SUOE.MI] => Array
(
[shortName] => ISHARES EUR CORP BOND SRI UCITS
[sector] =>
[industry] =>
[country] =>
[longBusinessSummary] =>
[currency] => EUR
[marketCap] =>
[logo_url] =>
[Anlageklasse] => Anleihen
[Anmerkungen] => Unternehmensnaleihen EUR
[Nachhaltigkeit] => 1
[Ist_Alternative] => 1
[weights] => -0.47997445382071
)
)
[risk] => 0.05323390949106
[return] => 1.1125842376311
)
Now I want to work with the single variables shortName, industry, etc.
When I tried to call the function with
print_r($json_data['assets']['CGGD.AS']['shortName']);
it worked perfectly fine. When I use
print_r($_POST['assets'][0][0]);
it is not working at all and gives me the following warning:
Warning: Undefined array key "assets" in
C:\xampp\htdocs\test\ergebnisdarstellung.php on line 52
Warning: Trying to access array offset on value of type null in
C:\xampp\htdocs\test\ergebnisdarstellung.php on line 52
The problem I have is that I will not know what name will be in the second brackets like CGGD.AS and because of this I can not use the working function. I will not now how long the array is either and numbers are not working. Because of this I do not know how to call the single variabless without using the name.
How can I call the function?

Answer 1

To get all shortName you can loop your array:
foreach ($json_data['assets'] as $key => $data) {
print_r($data['shortName']);
}
If you want just shortName of first element, then use current:
$item = current($json_data['assets']);
print_r($item['shortName']);

Answer 2

$arr = [
'assets' => [
'CGGD.AS' => [
'shortName' => 'iShares Global Govt Bond Climat',
// other fields omitted
],
'SUOE.MI' => [
'shortName' => 'ISHARES EUR CORP BOND SRI UCITS',
// other fields omitted
]
],
'risk' => 0.05323390949106,
'return' => 1.1125842376311
];
$assetsKeys = array_keys($arr['assets']);
$shortNames = array_column($arr['assets'], 'shortName');
$result = array_combine($assetsKeys, $shortNames);
print_r($result);
// This will print:
// Array
// (
// [CGGD.AS] => iShares Global Govt Bond Climat
// [SUOE.MI] => ISHARES EUR CORP BOND SRI UCITS
// )