Given the array $settings = ['theme' => null, 'language' => 'en'];, which of the following uses the null coalescing operator to correctly set $theme to 'default' if $settings['theme'] is null, and $language to 'en' if not set?
hard📝 Application Q8 of 15
PHP - Operators
Given the array $settings = ['theme' => null, 'language' => 'en'];, which of the following uses the null coalescing operator to correctly set $theme to 'default' if $settings['theme'] is null, and $language to 'en' if not set?
Step 1: Understand null coalescing for null and unset keys
The operator returns right operand if left is null or not set.
Step 2: Check each option
$theme = $settings['theme'] ?? 'default';
$language = $settings['language'] ?? 'en'; uses ?? correctly for both null and unset keys. $theme = $settings['theme'] ?: 'default';
$language = $settings['language'] ?: 'en'; uses ?: which treats empty strings and zero as false. $theme = isset($settings['theme']) ? $settings['theme'] : 'default';
$language = isset($settings['language']) ? $settings['language'] : 'en'; uses ternary with isset, which works but is longer. $theme = $settings['theme'] ??= 'default';
$language = $settings['language'] ??= 'en'; uses ??= which assigns if null but is not the question's requirement.
