laravel array_map 得到错误“array_map()：参数 #2 应该是一个数组”
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laravel array_map get error "array_map(): Argument #2 should be an array"
提问by monoy suronoy
I'm new on laravel. Why I'm always get error:
我是 Laravel 的新手。为什么我总是收到错误：
array_map(): Argument #2 should be an array ?
array_map()：参数#2 应该是一个数组？
whereas I'm assigning parameter array on this method?
而我在这个方法上分配参数数组？
this is my example code :
这是我的示例代码：
$products = Category::find(1)->products;
note : 1 category has many products
注意：1个类别有很多产品
this is the array from query :
这是来自查询的数组：
[{
"id": "1",
"name": "action figure",
"created_at": "2015-11-09 05:51:25",
"updated_at": "2015-11-09 05:51:25"
}, {
"id": "2",
"name": "manga",
"created_at": "2015-11-09 05:51:25",
"updated_at": "2015-11-09 05:51:25"
}]
when I'm trying the following code:
当我尝试以下代码时：
$results = array_map( function($prod) {
return $prod.name;
}, $products);
and I get the error like below:
我得到如下错误：
"array_map(): Argument #2 should be an array"
“array_map()：参数#2 应该是一个数组”
回答by PeterPan666
You should write
你应该写
$results = array_map(function ($prod) {
return $prod->name;
}, $products->toArray());
Because $productsis a Collection and not an array.
因为$products是一个集合而不是一个数组。
If you just want to have a list of product name use the pluckmethod
如果您只想获得产品名称列表，请使用该pluck方法
$results = $products->pluck('name')
In newer version of Laravel you should use $products->all();instead of toArraybecause in the case of an Eloquent collection, toArraywill try to convert your models to array too. allwill just return an array of your models as is.
在较新版本的 Laravel 中，您应该使用$products->all();而不是toArray因为在Eloquent集合的情况下，toArray也会尝试将您的模型转换为数组。all将按原样返回您的模型数组。
That being said, since you are on a Collection you can also use the mapmethod on it like so (which is exactly the same as using pluckin your case)
话虽如此，既然你在一个集合上，你也可以map像这样使用它的方法（这与pluck在你的情况下使用完全相同）
$products->map(function ($product) {
return $product->name;
});
