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将Laravel集合中的数组数组转换为带有json中数组的对象

分类: 技术问答 • 2022-05-25 21:58:47
问题描述：

我在Laravel API中生成了一系列类别和子类别，供我的客户端应用程序使用.

I am generating an an array of categories and subcategories in my Laravel API for use in my client side app.

我这样做是通过使用集合的 filter 和 map 方法来组织从数据库中提取的数据:

I'm doing this by using the collection's filter and map methods to organize the data pulled from the database:

// get the data from the category table
$categoryData = $categories->all()->categories();

// filter the data by category names we know we want and create the multi-dimensional array of the fields we need
$categoryList = $categoryData->filter(function ($value) {
    return $value['Category'] == "by Area of Interest" || $value['Category'] == "by Grade Level";
})
->map(function ($value) {
    return ['category' => $value['Category'], 'subCategory' => $value['Subcategory']];
});

dd($categoryList);

当我查看冲模和转储结果时，我得到了包含正确格式的项目数组的集合:

When I review the die and dump result, I get my collection with it's array of correctly formatted items:

如果我将其输出为数组，则使用:

And if I output it as an array with:

dd($categoryList->toArray());

我看到了我期望的多维数组.

I see the multi-dimensional array I would expect.

我遇到的问题是当我尝试将其输出为json以便客户端应用程序使用时.

The problem I'm running into is when I try to output it as json for my client app to consume.

dd($ categoryList-> toJson());

dd($categoryList->toJson());

如果我输出为json，则会得到一个对象，该对象包含php数组索引作为属性，而php子数组作为分配给这些属性的对象.

If I output as json I get an object that contains the php array indexes as properties and the php sub arrays as objects assigned to those properties.

我想要的是一个包含对象数组的json对象.例如

What I want is a json object that contains an array of objects. e.g.

$categoryList = [['category' => 'test', 'subCategory' => 'test'], ['category' => 'test', 'subCategory' => 'test']];
dd(json_encode($categoryList));

哪个输出:

我的催收电话有问题吗?

Is there something I'm doing wrong with my collection calls?

每个霍格宾的评论:

对 $ categories-> all()-> categories(); 的调用将返回类别数据的集合，然后我将其操纵以获取列表.

The call to $categories->all()->categories(); returns a collection of category data that I then manipulate to get my list. 

$categoryData = $categories->all()->categories();
dd($categoryData);

产量:

答

问题在于，索引是您尝试从数组中获取数组时从雄辩的集合中获取的类别的ID.

The problem is that the indexes are the ids of categories which You'll get from eloquent collection when You try to make array from it.

如果您想要一个干净的对象数组，我建议您这样做:

If you want to have a clean array of objects, I suggest doing this:

json_encode(array_values($categoryList->toArray()));

克里斯的最终实施

上面的解释和函数调用使我得到了所需的最终结果.通过这些函数调用确认它可以正常工作后，我查看了 Collection 类方法，以了解如何使用该类实现它.这是我所做的:

Final implementation by Chris

The above explanation and function calls got me the end result I needed. After confirming it worked via these function calls I looked at the Collection class methods to see how I could implement it using the class. Here's what I did:

$categoryList = $categoryData->filter(function ($value) {
    return $value['Category'] == "by Area of Interest" || $value['Category'] == "by Grade Level";
})
->map(function ($value) {
    return ['category' => $value['Category'], 'subCategory' => $value['Subcategory']];
})
->values()
;

如果您查看 Collection 类的 values()方法，则它的作用相同:

If you look at the Collection class' values() method, it's doing the same thing:

由于Laravel集合 items 作为数组存储，因此不需要 toArray()方法调用.

Since the Laravel Collection items are stored as an array, the toArray() method call is not needed.

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