It is a null coalescing operator that works with null values.
It has two parts: the first part is the variable, and the second part is the value.
It first checks if the variable is null or not.
It returns the value of the variable if it is not null; otherwise, it returns the default value.
Syntax:
$variable = $variable ?? default_value;Example:
$username = null;
$name = $username ?? "Guest";
echo $name;Output:
Guest