PHP获取多维数组指定的值在数组第几列

<?php
$user = array(  
    0 => array(  
        &#39;id&#39;    => 1,  
        &#39;name&#39;  => &#39;张三&#39;,  
        &#39;email&#39; => &#39;zhangsan@qq.com&#39;,  
    ),  
    1 => array(  
        &#39;id&#39;    => 3,  
        &#39;name&#39;  => &#39;李四&#39;,  
        &#39;email&#39; => &#39;lisi@qq.com&#39;,  
    ),  
    2 => array(  
        &#39;id&#39;    => 5,  
        &#39;name&#39;  => &#39;王五&#39;,  
        &#39;email&#39; => &#39;wangwu@qq.com&#39;,  
    )
);  
print_r(array_column($user,&#39;id&#39;));
?>