// 声明关联数组
$arr = array(
    "1" => "加",
    "2" => "减",
    "3" => "乘",
    "4" => "除"
);
// 关联数组中删除键1及其值
unset($arr['1']);
// 显示数组元素
var_dump($arr);

// 声明关联数组
$arr = array(
    "1" => "春",
    "2" => "夏",
    "3" => "秋",
    "4" => "冬",
);
// 从关联数组中删除键1及其值
$result = array_diff_key($arr,
    array_flip((array) ['1']));
// 显示数组元素
var_dump($result);

array_values(array)

$arr = array('key1'=>'value1','key2'=>'value2','key3'=>'value3');
$arr2 = array_values($arr);
print_r($arr2);
?>