<?php
$array1 = ['user_firstname' => 'Jack', 'user_lastname' => 'Smith', 'user_address_1' => '123'];
$data = [];
foreach($array1 as $key=>$value){
$tokens = explode('_', $key, 2); // split the string in an array of strings, using _ as a delimitor.
// the 2 is the maximun number of tokens to split the string into, look at explode() docs
$keyName = end($tokens); // use last element of the array
$data[$keyName] = $value; // assign value to key
}
print_r($data);
Array
(
[firstname] => Jack
[lastname] => Smith
[address_1] => 123
)
Output for 8.3.5
Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
Array
(
[firstname] => Jack
[lastname] => Smith
[address_1] => 123
)