取消多維數組中的數據

Question

我有csv [] []。我如何使用每個循環來取消行中的數據？

for each ($index) { 
if (conditions to meet) { 
unset(csv[$index]);  
} 
} 

Answer 1

試試這個：

foreach ($csv as $key => $value) { 
     unset($csv[$key]); 
    } 

Answer 2

http://docs.php.net/manual/en/control-structures.foreach.php說：

爲了能夠直接修改環路普瑞森$值中數組元素與＆。在這種情況下，價值將由 reference分配。

這就是你在使用兩個foreach循環時應該用來修改行的單個元素。

<?php 
$csv = [ 
    [1,2,3,4,5], 
    [2,3,4,5,6], 
    [3,4,5,6,7], 
    [4,5,6,7,8], 
]; 

// make $row a reference 
// so that unset($row[...]) affects $csv and not only a "copy". 
foreach($csv as &$row) { 
    foreach($row as $key=>$column) { 
     if (0===$column%2) { // e.g. remove all even elements 
      unset($row[$key]); 
     } 
    } 
} 

var_export($csv); 

打印

array (
    0 => 
    array (
    0 => 1, 
    2 => 3, 
    4 => 5, 
), 
    1 => 
    array (
    1 => 3, 
    3 => 5, 
), 
    2 => 
    array (
    0 => 3, 
    2 => 5, 
    4 => 7, 
), 
    3 => 
    array (
    1 => 5, 
    3 => 7, 
), 
) 

或（相同的輸出），而foreach循環。

<?php 
$csv = [ 
    [1,2,3,4,5], 
    [2,3,4,5,6], 
    [3,4,5,6,7], 
    [4,5,6,7,8], 
]; 

$csv = array_map(
    function($row) { 
     return array_filter(
      $row, 
      function($col) { 
       return 0!==$col%2; 
      } 
     ); 
    }, 
    $csv 
); 

var_export($csv);