无法从嵌套数组中删除空元素

Question

我有一个数组，$row2。

在 $row2 中存在两个数组。 $row2 的输出为：

Array
(
    [0] => Array
        (
            [Proposal_id] => 9
            [row] => 1
            [col1] => 2
            [col2] => 2
            [col3] =>
            [col4] =>
            [col5] =>
            [Type] => customtbl
            [Invoice_term] =>
            [Qoute] =>
            [Rate_per_hour] =>
            [Total] =>
        )

    [1] => Array
        (
            [Proposal_id] => 9
            [row] => 2
            [col1] => 3
            [col2] => 4
            [col3] =>
            [col4] =>
            [col5] =>
            [Type] => customtbl
            [Invoice_term] =>
            [Qoute] =>
            [Rate_per_hour] =>
            [Total] =>
        )

)

我想从数组中删除空元素，但我不能这样做。

我尝试了以下方法：

array_filter($row2);
array_filter($row2, function($var){return !is_null($var);});
array_diff($rows2, array("null", ""));

Answer 1

在array_map 中使用array_filter。 请记住，您可能想要运行不同的条件而不是 if($value)，因为这不仅会验证空值，还会验证零和空字符串。

array_map(function($var) {
    return array_filter($var, function($value) {
        if ( !is_null($value) )
            return $value;
    });
},$row2);

Answer 2

如果您使用array_map 和array_filter，我有一个单一的解决方案可以从多维数组中过滤出null 值，

    $array = [
    ['Proposal_id' => 9,
     'row' => 1,
     'col1' => 2, 
     'col2' => 2, 
     'col3' => null,
     'col4' => null,
     'col5' =>  null,
     'Type' => 'customtbl',
     'Invoice_term' => null,  
     'Qoute' => null,
     'Rate_per_hour' => null,  
     'Total' => null,
    ],
    [   
        'Proposal_id' => 9,
        'row' => 1,
        'col1' => 2, 
        'col2' => 2 ,
        'col3' => null,
        'col4' => null,
        'col5' =>  null,
        'Type' => 'customtbl',
        'Invoice_term' => null,  
        'Qoute' => null,
        'Rate_per_hour' => null,  
        'Total' => null,
    ]
];
$af = array_filter(array_map('array_filter', $array));
print '<pre>';
print_r($af);
print '</pre>';

输出：

 Array
(
    [0] => Array
        (
            [Proposal_id] => 9
            [row] => 1
            [col1] => 2
            [col2] => 2
            [Type] => customtbl
        )

    [1] => Array
        (
            [Proposal_id] => 9
            [row] => 1
            [col1] => 2
            [col2] => 2
            [Type] => customtbl
        )

)

演示：https://eval.in/975240