获取多维数组中具有相同索引的所有数组元素 - Getting all array elements with same index in multidimensional array

Getting all array elements with same index in multidimensional array

请问一个基本问题。有人可以帮助我获取所有三个主要类别字符串（要做的事情、交通和生活）。我只发现了如何单独获得它们

$categories[0]->maincategory;

但是我怎样才能得到这三个呢？最好的感谢！

Array
(
[0] => stdClass Object
    (
        [id] => 2
        [maincategory] => Things to Do
        [category] => Activities and  Attractions
    )
[1] => stdClass Object
    (
        [id] => 6
        [maincategory] => Transportation
        [category] => Airport Transfers
    )
[2] => stdClass Object
    (
        [id] => 11
        [maincategory] => Living
        [category] => Broadband Internet
    )
)

类似

foreach ($stdClass as $sclass){
    if(!is_array($sclass)){
     echo $sclass.' ';
     }else{
    foreach ($sclass as $scl){

    echo $scl.' ';
    }
    }
    }

简单的foreach循环就可以了。

foreach ($categories as $category) {
  echo $category->maincategory;
}