排序問題和使用 array_multisort() 數組大小不一致的警告

Question

如您所見，二維數組如下：

Array ( [0] => Array ( [0] => Prishtina [1] => Bregu i Diellit [2] => 7 ) 
    [1] => Array ( [0] => Prishtina [1] => Tasligje [2] => 4 ) 
    [2] => Array ( [0] => Prishtina [1] => Bregu i Diellit [2] => 4 ) 
    [3] => Array ( [0] => Prishtina [1] => Bregu i Diellit [2] => 3 ) 
    [4] => Array ( [0] => Prishtina [1] => Bregu i Diellit [2] => 9 ) 
    [5] => Array ( [0] => Prishtina [1] => Lakrishte [2] => 4 ) 
    [6] => Array ( [0] => Prishtina [1] => Lakrishte [2] => 6 ) 
    [7] => Array ( [0] => Prishtina [1] => Lakrishte [2] => 1 ) 
    [8] => Array ( [0] => Prishtina [1] => Ulpiana [2] => 3 ) 
    [9] => Array ( [0] => Prishtina [1] => Ulpiana [2] => 6 ) 
    [10] => Array ( [0] => Prishtina [1] => Ulpiana [2] => 5 ) 
    [11] => Array ( [0] => Prishtina [1] => Ulpiana [2] => 8 ) 
    [12] => Array ( [0] => Prishtina [1] => Ulpiana [2] => 4 ) 
    [13] => Array ( [0] => Prishtina [1] => Ulpiana [2] => 8 ) 
    [14] => Array ( [0] => Prishtina [1] => Velania [2] => 2 ) 
    [15] => Array ( [0] => Prishtina [1] => Velania [2] => 5 ) 
    [16] => Array ( [0] => Prishtina [1] => Velania [2] => 1 ) 
    [17] => Array ( [0] => Prishtina [1] => Dragodan [2] => 9 ) 
    [18] => Array ( [0] => Prishtina [1] => Dragodan [2] => 7 ) 
    [19] => Array ( [0] => Prishtina [1] => Dragodan [2] => 10 ) 
    [20] => Array ( [0] => Prishtina [1] => Velania [2] => 11 ) 
    [21] => Array ( [0] => Mitrovica [1] => Qender [2] => 5 ) 
    [22] => Array ( [0] => Mitrovica [1] => Qender [2] => 3 ) 
    [23] => Array ( [0] => Mitrovica [1] => Tavnik [2] => 6 ) 
    [24] => Array ( [0] => Mitrovica [1] => Tavnik [2] => 9 ) 
    [25] => Array ( [0] => Mitrovica [1] => Bair [2] => 10 ) 
    [26] => Array ( [0] => Mitrovica [1] => Bair [2] => 12 ) 
    [27] => Array ( [0] => ) ) 

我正在嘗試使用以下代碼按第 3 列排序：

foreach ($final_array as $roww){
    $sort_column[]= $roww[2];   // 2 = your example
    array_multisort($sort_column, $final_array);
}

但是，當我打印時：

for ($row = 0; $row < count($final_array); $row++)
{
    foreach($final_array[$row] as $key => $value)
        {
            echo $value;
        }
        echo "<br/>";
 }

當我打印時，它會排序並打印按第 3 列排序的數組，但是它給我帶來了這些警告

Warning: array_multisort() [function.array-multisort]: Array sizes are inconsistent in   C:\xampp\htdocs\test\test.php on line 35
 Notice: Undefined offset: 2 in C:\xampp\htdocs\test\test.php on line 34

我不確定為什么會發生這種情況，這對我來說沒有意義，一切正常，但是我需要這些警告！！

Answer 1

這是一個警告，因為在索引27處存在對數組的未定義引用。 警告說您正在嘗試使用該值，但它不存在。

再看看你的數組

Answer 2

array_multisort() 如果用於一次對多個數組進行排序，則回顯警告，如果選擇執行多排序的所有數組的大小不同：

$arr = array(
    'UK' => array(
        'John' => 'Toyota',
        'Alice' => 'Opel',
        'Evan' => 'Fiat',
        'Gregory' => 'Mitsubishi'
    ),
    'Germany' => array(
        'Bruno' => 'Opel',
        'Andreas' => 'Mercedes',
        'Klaus' => 'Porsche',
    )
);

看？ 兩個數組中的元素數量不同。 因此，即使選項不同，array_multisort 也會嘗試以相同的方式對這些數組進行排序：

array_multisort(
    $arr['Germany'], SORT_ASC, SORT_NATURAL,
    $arr['UK'], SORT_DESC, SORT_NUMERIC
    );

這將打印如下警告：警告：array_multisort()：數組大小在 (...)

Answer 3

當在兩個不相關的多維數組中使用相同的一個或多個鍵名時，會出現另一個會拋出“數組大小不一致”的情況。 如果在第二個多維數組中設置列之前清除鍵名，您仍然可以使用相同的鍵名。 如果不鼓勵這樣做，我很想知道原因。