PHP - 检查一个数组中的值是否存在于另一个数组多维数组中

Question

我有以下两个数组。

这是一个平面数组（字符串：$second_names）：

Array ( [0] => Cars [3] => Bikes [8] => Trucks ) //$second_names

我有这个多维数组 - (string: $premiumCatArraySets):

Array
(
    [0] => Array
        (
            [primary-category] => Automobiles
            [secondary-category] => Cars
            [tertiary-category] => Fiat Punto
        )
[1] => Array
    (
        [primary-category] => Automobiles
        [secondary-category] => Cars
        [tertiary-category] => BMW
    )

[2] => Array
    (
        [primary-category] => Automobiles
        [secondary-category] => Bikes
        [tertiary-category] => Honda
    )

[4] => Array
    (
        [primary-category] => Automobiles
        [secondary-category] => Trucks
        [tertiary-category] => Iveco
    )

[6] => Array
    (
        [primary-category] => Automobiles
        [secondary-category] => Cars
        [tertiary-category] => Mercedes
    )

[9] => Array
    (
        [primary-category] => Automobiles
        [secondary-category] => Cars
        [tertiary-category] => Toyota
    )

我正在尝试使用in_array查看平面数组中的值是否存在并输出汽车的品牌。

这是我尝试过的

foreach ($second_names as $second_name) {//Vechile type e.g. car, truck, bike
    if(in_array($second_name, $premiumCatArraySets)){
        echo '<h2>'.$second_name.'</h2>';
        foreach ($third_names as $third_name) {// e.g. Fiat, BMW, Toyota
            echo $third_name.'<br/>';
        }
    }
}

if(in_array($second_name, $premiumCatArraySets)){ 的行似乎没有显示任何内容。

Answer 1

如果我的理解是正确的，您必须从第二个数组中为第一个数组中的每辆车获取车辆品牌。您可以执行以下操作。这是一个基本脚本。

<?php

$vehicles = ['Cars', 'Bikes', 'Trucks'];

$details = [
    [
        'primary-category' => 'Automobiles',
        'secondary-category' => 'Cars',
        'tertiary-category' => 'BMW'
    ],
    [
        'primary-category' => 'Automobiles',
        'secondary-category' => 'Trucks',
        'tertiary-category' => 'Benz'
    ]
];

foreach ($vehicles as $vehicle) {
    foreach ($details as $detail) {
        if ($vehicle == $detail['secondary-category']) {
            echo $detail['tertiary-category'];
            break;
        }
    }
}

?>

Answer 2

试试

$output = [];
foreach($premiumCatArraySets as $key => $value){    
    if(in_array($value["secondary-category"],$second_names)){
        if(!isset($output[$value["secondary-category"]])){
            $output[$value["secondary-category"]]  = [];
        }        
        $output[$value["secondary-category"]][] = $value["tertiary-category"];
    }
}
foreach($output as $key => $value){ 
    echo '<h2>'.$key."</h2>";
        echo implode(", ",$value)."<br/>";
}

---

输出

Cars    
Fiat Punto, BMW, Mercedes, Toyota

Bikes    
Honda

Trucks    
Iveco

参考：Demo

Answer 3

使用call_user_func_array、array_merge_recursive、array_keys、array_flip、array_intersect_key和implode函数的解决方案：

// grouping each category preserving the position of each item
$groups = call_user_func_array('array_merge_recursive', $premiumCatArraySets);
foreach ($second_names as $name) {
    $indexes = array_flip(array_keys($groups['secondary-category'], $name));
    echo '<h2>'.$name.'</h2>';
    echo implode(", ", array_intersect_key($groups['tertiary-category'], $indexes)) .'<br/>';
}

输出：

<h2>Cars</h2>Fiat Punto, BMW, Mercedes, Toyota<br/><h2>Bikes</h2>Honda<br/><h2>Trucks</h2>Iveco<br/>