HH\Lib\C\nfirst
Returns the first element of the given Traversable, or null if the Traversable is null or empty
namespace HH\Lib\C;
function nfirst<T>(
?Traversable<T> $traversable,
): ?T;
- For non-null Traversables, see
C\first. - For non-empty Traversables, see
C\firstx. - For single-element Traversables, see
C\onlyx.
Time complexity: O(1) Space complexity: O(1)
Parameters
?Traversable<T>$traversable
Returns
?T
Examples
$strings = vec["a", "b", "c"];
$first_string = C\nfirst($strings);
echo "First string in traversable: $first_string \n";
//Output: First string in traversable: a
$empty_traversable = vec[];
$first_element = C\nfirst($empty_traversable);
$first_element_as_string = $first_element ?? "null";
echo "First element in empty traversable: $first_element_as_string";
//Output: First element in empty traversable: null