php - 如何填充这个 PHP 数组？

Question

我有一个外包数据：

http://example.com/data/news.json

这是解码后的示例结果：

Array
(
    [popular] => Array
        (
            [last_week] => Array
                (
                    [0] => Array
                        (
                           [title] => Business 1
                            [category] => blog/business/local
                        )
                    [1] => Array
                        (
                        [title] => Health 1
                        [category] => blog/health/skincare
                    )
                [2] => Array
                    (
                        [title] => Business 2
                        [category] => blog/business/local
                    )
                [3] => Array
                    (
                        [title] => Health 2
                        [category] => blog/health/skincare
                    )
            )
    )

)

我使用以下方法来显示它：

$url = 'http://example.com/data/news.json';
$json = file_get_contents($url);
if(!empty($json)) {
$json_data = json_decode($json, true);
$popular_last_week = $json_data['popular']['last_week'];
$count = count($popular_last_week);
$result .= $count.' last week popular article' . "\n";
for ($i = 0;  $i <$count; $i++) {
$result .= 'Title : '.$popular_last_week[$i]['title'] . "\n";
$result .= 'Category : '.$popular_last_week[$i]['category'] . "\n\n";
}
echo $result;
}

输出数据为：

4 上周热门文章

标题：业务 1
类别：博客/业务/本地

标题：健康 1
类别：博客/健康/护肤

标题：业务 2
类别：博客/业务/本地

标题：健康 2
类别：博客/健康/护肤

问题是如何显示输出如下：

2 上周热门商业文章

标题：业务 1
类别：业务

标题：业务 2
类别：业务

2 上周热门健康文章

标题：健康 1
类别：健康

标题：健康 2
类别：健康

帮助将不胜感激！谢谢你。

Answer 1

$url = 'http://example.com/data/news.json';
$json = file_get_contents($url);
if(!empty($json)) {
    $json_data = json_decode($json, true);
    $popular_last_week = $json_data['popular']['last_week'];

    //  This loop will group all entries by category.
    $categories = array();
    foreach ($popular_last_week as $item) {
        $categories[$item['category']][] = $item['title'];
    }

    //  This loop will echo the titles grouped by categories.
    foreach ($categories as $category => $titles) {
        $result = count($titles) . ' popular in "' . $category . '"' . "\n";
        foreach ($titles as $title) {
            $result .= 'Title: ' . $title . "\n";
        }
        echo $result;
    }
}

Answer 2

你的意思是你只想显示2个项目？您需要使用for循环。

for ($i = 0;  $i < 2; $i++) {
    # display for $i
}

更新：

啊，我想我明白了。您应该使用foreach循环并循环两次：

$categoryItems = array();
foreach ($popular_last_week as $item) {
    $categoryItems[$item['category']][] = $item['title'];
}
foreach ($categoryItems as $category => $items) {
    $result .= count($items) . ' popular in category ' . $category;
    foreach ($items as $item){
        $result .= 'Title: ' . $item['title'] . "\n";
    }
}
echo $result;