Original answer, but costly (O(n)):
array_shift(array_values($array));
In O(1):
array_pop(array_reverse($array));
Other use cases, etc…
If modifying (in the sense of resetting array pointers) of $array
is not a problem, you might use:
reset($array);
This should be theoretically more efficient, if a array “copy” is needed:
array_shift(array_slice($array, 0, 1));
With PHP 5.4+ (but might cause an index error if empty):
array_values($array)[0];