如何在类别标题中显示类别项目

Question

I have an array like below

Array
(
    [0] => stdClass Object
        (
            [id] => 1
            [cat_id] => 1
            [item_name]=>test1
            [cat_name] => Normal
        )

    [1] => stdClass Object
        (
            [id] => 2
            [cat_id] => 2
            [item_name]=>test2
            [cat_name] => Featured
        )

    [2] => stdClass Object
        (
            [id] => 3
            [cat_id] => 2
            [item_name]=>test3
            [cat_name] => Featured
        )  
)  

And I want the result to look like this

Normal

test1

Featured

test2  |  test3

I have try this so far:

<?php
foreach($rows as $row){
    echo '<h2>'.$row->cat_name.'</h2>';
    echo '<p>'.$row->item_name.'</p>';
}
?>

But it shows the heading with each of the item.Can someone help me to sort this out.

Thanks

Answer 1

So you want to group them? Here's a function for that:

function groupBy($arr, $func) {
    $groups = [];

    foreach($arr as $item) {
        $group = $func($item);

        if(array_key_exists($group, $groups))
            $groups[$group][] = $item;
        else
            $groups[$group] = [$item];
    }

    return $groups;
}

Use it like so:

$groups = groupBy($rows, function($row) { return $row->cat_name; });

foreach($groups as $name => $items) {
    echo "<h2>$name</h2>";

    foreach($items as $item)
        echo "<p>{$item->item_name}</p>";
}

And here's a demo. If you don't have the luxury of PHP 5.3, then you can make it more specialized:

function groupBy($arr, $prop) {
    $groups = array();

    foreach($arr as $item) {
        $group = $item->$prop;

        if(array_key_exists($group, $groups))
            $groups[$group][] = $item;
        else
            $groups[$group] = array($item);
    }

    return $groups;
}
...
$groups = groupBy($rows, 'cat_name');

foreach($groups as $name => $items) {
    echo "<h2>$name</h2>";

    foreach($items as $item)
        echo "<p>{$item->item_name}</p>";
}

Demo on PHP 5.2.17