Php 如何在数组中插入if函数

我有一个数组

$data\U数组=

array
    (
        "limit" => $limit,
        "page_number" => $page,
        "books" => $books
    );

我希望如果设置了$books，那么数组应该是

array
    (
        "limit" => $limit,
        "page_number" => $page,
        "books" => $books
    );

array
(
    "limit" => $limit,
    "page_number" => $page
);

如果未设置变量$books，则数组应为

array
    (
        "limit" => $limit,
        "page_number" => $page,
        "books" => $books
    );

array
(
    "limit" => $limit,
    "page_number" => $page
);

谁能帮帮我吗

if(isset($books))
{
    $data_array=array
    (
        "limit" => $limit,
        "page_number" => $page,
        "books" => $books
    );
}
else
{
    $data_array=array
    (
        "limit" => $limit,
        "page_number" => $page
    );
}

---

我认为这应该可以完成这项工作。

最好的方法是使用

$data_array = array
(
    "limit" => $limit,
    "page_number" => $page
);

if(isset($books)){
    $data_array['books'] = $books;
}

---

如果我有一个很长的值和变量数组，如果一个长数组使用5或6次，我将很难使用它。。原因代码占用的行数较少，易于维护