javascript - How to turn an array into a negative number in php

Question

1. I have an array array(1,2,3); I need it to become a negative number when inserting it into the database

2. The front-end input table displays a positive number, and the back-end becomes a negative number before inserting it into the database. How to achieve this?

Answer 1

$arr1 = array(1,2,3);
$arr2 = array();
foreach($arr1 as $v){

  $arr2[] = -$v;

}

Answer 2

$a = array(1, 2, 3, 4, 5);
$a = array_map(function ($item) {
    return $item<0?$item:-$item;
}, $a);

Answer 3

Loop, take negative value and save to database