PHP从数组的两侧删除空项

$data = array(1, 2, 3, 4, 5, 6, 7, 8, 9);

// 从数组的左侧删除空项
$result = array_filter($data, function($v) {
    return $v !== '';
});

print_r($result);

// 从数组的右侧删除空项
$result = array_filter($data, function($v) {
    return $v !== '';
}, ARRAY_FILTER_USE_BOTH);

print_r($result);

Array
(
    [1] => 1
    [3] => 3
    [5] => 5
    [7] => 7
)
Array
(
    [0] => 1
    [2] => 2
    [4] => 4
    [6] => 6
    [8] => 8
)