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Asked:2023-03-09 18:28:43 +0000 UTC2023-03-09 18:28:43 +0000 UTC

为什么使用array_filter(php)过滤器时，只显示过滤后的参数，而不显示整个数组元素？

  • 772

我有一系列按价格范围过滤的产品$minPrice = 1000; $maxPrice = 4000; 

$json_array = [
"0" => [
            'racquetId' => 3457,
            'country' => 'USA',
            'product' => 'Wilson',
            'price' => 990,
            'currency' => 'EUR',
        ],

    "1" => [
            'racquetId' => 5678,
            'country' => 'France',
            'product' => 'Babolat',
            'price' => 2310,
            'currency' => 'EUR'
        ],

    "2" => [
            'racquetId' => 1368,
            'country' => 'France',
            'product' => 'Babolat',
            'price' => 4703,
            'currency' => 'EUR',
        ],

    "3" => [
            'racquetId' => 4568,
            'country' => 'Austria',
            'product' => 'Head',
            'price' => 1480,
            'currency' => 'EUR',
            'startPrice' => 1850,
        ]
];

为什么使用递归时显示的是整个过滤后的数组？

function recurse_arr($arr,&$filtered_arr2,$minPrice,$maxPrice){
foreach($arr as $key=>$value) {    
    if(isset($value["price"])) {
        if($value["price"] >= $minPrice && $value["price"] <= $maxPrice) {
            $filtered_arr2[$key] = $value;
        }  
    }
   
    //If there's an array within array then recall the function.
    elseif(gettype($value) == 'array') {
        recurse_arr($value,$filtered_arr2);
    }
 
}
 
return $filtered_arr2;
}
 
$filtered_arr2 = [];
print_r(recurse_arr($json_array,$filtered_arr2,$minPrice,$maxPrice));

并且在使用时array_filter

$filtered_arr2 = [];
print_r(recurse_arr($json_array,$filtered_arr2,$minPrice,$maxPrice));

$filtered_arr = [];
foreach($json_array as $array=>$racquet) {
    
    array_push($filtered_arr,array_filter($racquet,function($v,$k) use($minPrice,$maxPrice){
        return $k == 'price' && $v >= $minPrice && $v <= $maxPrice;
        
    },ARRAY_FILTER_USE_BOTH));
    
}
//print_r(array_merge(...$filtered_arr));  //Array ([price] => 1480)
print_r($filtered_arr);

这是这种形式：

(
    [0] => Array
        (
        )

    [1] => Array
        (
            [price] => 2310
        )

    [2] => Array
        (
        )

    [3] => Array
        (
            [price] => 1480
        )
)

整个代码及其工作在沙箱中进行了演示

php

1 个回答

  1. Best Answer

    这样写是正确的：

    $filtered_arr = array_filter(
    $json_array,
    function ($v) use ($minPrice,$maxPrice) {   
        return $v['price'] >= $minPrice && $v['price'] <= $maxPrice; 
    }
);

    并考虑到自7.4版以来可用的箭头功能：

    $filtered_arr = array_filter(
    $json_array,
    fn ($v) => $v['price'] >= $minPrice && $v['price'] <= $maxPrice
);
    • 1

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