Null-Safe Operator in the TYPO3 area

In PHP, you're sure to come across variables that don't contain an expected object or arrays that don't have a certain key set. Various IF conditions may also have been inserted. Here are a few examples of how you can write smart code using a null-save operator.

PHP

Here is a short example of arrays:

# Old
$color = '';
if (array_key_exists('color', $this->settings)) {
    $color = $this->settings['color'];
}

# New
$color = $this->settings['color'] ?? '';

And here for function and property calls:

# Old
$address = $customer->getAddress();
$country = null;
if ($address->getCountry() !== null) {
    $country = $address->getCountry();
}

# Not quite so old
$address = $customer->getAddress();
$country = $address ? $address->getCountry() : null;

# New
$country = $customer->getAddress()?->getCountry(); 

# Alternative example
$tsfe = $GLOBALS['TSFE'] ?? null;
$id = (int)$tsfe?->id;

TypoScript

The topic has also already arrived in TypoScript. Problems can quickly arise, especially when using conditions. Here is an example when $GLOBALS['TSFE'] is not available (e.g. in the backend or CLI context):

# Old
[getTSFE().type == 123]

# New
[getTSFE()?.type == 123]

JavaScript

We have one more. In JavaScript you can also avoid unnecessary IF conditions with a null-save operator:

# Old
let myValue = '';
const element = document.querySelector('[data-foo]');
if (element !== null) {
    myValue = element. getAttribute('data-foo');
}

# New
let myValue = document.querySelector('[data-foo]')?.getAttribute('data-foo');