SplDoublyLinkedList::add()

(PHP 5 >= 5.5.0, PHP 7)

Add/insert a new value at the specified index

说明

publicSplDoublyLinkedList::add(mixed $index, mixed $newval) : void

Insert the value$newvalat the specified$index, shuffling the previous value at that index (and all subsequent values) up through the list.

参数

$index

The index where the new value is to be inserted.

$newval

The new value for the$index.

返回值

没有返回值。

错误／异常

ThrowsOutOfRangeExceptionwhen$indexis out of bounds or when$indexcannot be parsed as an integer.

$a = new SplDoublyLinkedList;
$arr=[1,2,3,4,5,6,7,8,9];
for($i=0;$i<count($arr);$i++){
  $a->add($i,$arr[$i]);
}
print_r($a);
//Output:
SplDoublyLinkedList Object
(
  [flags:SplDoublyLinkedList:private] => 0
  [dllist:SplDoublyLinkedList:private] => Array
    (
      [0] => 1
      [1] => 2
      [2] => 3
      [3] => 4
      [4] => 5
      [5] => 6
      [6] => 7
      [7] => 8
      [8] => 9
    )
)

Maybe the basic usage is like this i think..
$a = new \SplDoublyLinkedList;
if ($a instanceof \SplDoublyLinkedList) {
  $a->add(0, 'Paulus');
  $a->add(1, 'Gandung');
  $a->add(2, 'Prakosa');
  // then, iterate over that because \SplDoublyLinkedList
  // is implementing \Iterator interface.
  foreach ($a as $value) {
    echo sprintf("%s\n", $value);
  }
}