unset:
<?php
$arr=[1,2,3,4,5];
var_dump($arr);
echo "<br/>";
echo count($arr);
echo "<hr/>";
unset($arr[2]);
var_dump($arr);
echo "<br/>";
echo count($arr);
?>
unset删除数组元素是不会重建索引的。
array array_splice ( array &$input , int $offset [, int $length = count($input) [, mixed $replacement = array() ]] )
//正数 $arrs = [1,2,3,4,5,6];
array_splice($arrs,2,3);
print_r($arrs);
//output //Array ( [0] => 1 [1] => 2 [2] => 6 )
//负数 $arrs = [1,2,3,4,5,6];
array_splice($arrs,2,-3);
print_r($arrs);
//output //Array ( [0] => 1 [1] => 2 [2] => 4 [3] => 5 [4] => 6 )
array_splice()函数是会重建索引的