如何将一个新项目插入到数组的任何位置,例如在数组的中间?


当前回答

这也是一个有效的解决方案:

function array_insert(&$array,$element,$position=null) {
  if (count($array) == 0) {
    $array[] = $element;
  }
  elseif (is_numeric($position) && $position < 0) {
    if((count($array)+position) < 0) {
      $array = array_insert($array,$element,0);
    }
    else {
      $array[count($array)+$position] = $element;
    }
  }
  elseif (is_numeric($position) && isset($array[$position])) {
    $part1 = array_slice($array,0,$position,true);
    $part2 = array_slice($array,$position,null,true);
    $array = array_merge($part1,array($position=>$element),$part2);
    foreach($array as $key=>$item) {
      if (is_null($item)) {
        unset($array[$key]);
      }
    }
  }
  elseif (is_null($position)) {
    $array[] = $element;
  }  
  elseif (!isset($array[$position])) {
    $array[$position] = $element;
  }
  $array = array_merge($array);
  return $array;
}

获奖者: http://binarykitten.com/php/52-php-insert-element-and-shift.html

其他回答

要将元素插入到具有字符串键的数组中,您可以这样做:

/* insert an element after given array key
 * $src = array()  array to work with
 * $ins = array() to insert in key=>array format
 * $pos = key that $ins will be inserted after
 */ 
function array_insert_string_keys($src,$ins,$pos) {

    $counter=1;
    foreach($src as $key=>$s){
        if($key==$pos){
            break;
        }
        $counter++;
    } 

    $array_head = array_slice($src,0,$counter);
    $array_tail = array_slice($src,$counter);

    $src = array_merge($array_head, $ins);
    $src = array_merge($src, $array_tail);

    return($src); 
} 

通常,使用标量值:

$elements = array('foo', ...);
array_splice($array, $position, $length, $elements);

要在数组中插入一个数组元素,不要忘记将数组包装在数组中(因为它是一个标量值!):

$element = array('key1'=>'value1');
$elements = array($element);
array_splice($array, $position, $length, $elements);

否则,数组的所有键都将逐条添加。

$result_array = array();
$array = array("Tim","John","Mark");
$new_element = "Bill";
$position = 1; 

for ($i=0; $i<count($array); $i++)
    {
      if ($i==$position)
       {
          $result_array[] = $new_element;
       }
       $result_array[] = $array[$i];
    }

print_r($result_array); 

// Result will Array([0] => "Tim",[1] => "Bill", [2] => "John",[1] => "Mark")

这也是一个有效的解决方案:

function array_insert(&$array,$element,$position=null) {
  if (count($array) == 0) {
    $array[] = $element;
  }
  elseif (is_numeric($position) && $position < 0) {
    if((count($array)+position) < 0) {
      $array = array_insert($array,$element,0);
    }
    else {
      $array[count($array)+$position] = $element;
    }
  }
  elseif (is_numeric($position) && isset($array[$position])) {
    $part1 = array_slice($array,0,$position,true);
    $part2 = array_slice($array,$position,null,true);
    $array = array_merge($part1,array($position=>$element),$part2);
    foreach($array as $key=>$item) {
      if (is_null($item)) {
        unset($array[$key]);
      }
    }
  }
  elseif (is_null($position)) {
    $array[] = $element;
  }  
  elseif (!isset($array[$position])) {
    $array[$position] = $element;
  }
  $array = array_merge($array);
  return $array;
}

获奖者: http://binarykitten.com/php/52-php-insert-element-and-shift.html

$a = array(1, 2, 3, 4);
$b = array_merge(array_slice($a, 0, 2), array(5), array_slice($a, 2));
// $b = array(1, 2, 5, 3, 4)