Creating an array from recursive function in codeigniter - php

Question

I want to create an array using recursion in Codeigniter. my function make_tree() in controller is :
function make_tree($customer_id,$arr = array()){
$ctree = $this->customer_operations->view_customer_tree($customer_id);
foreach($ctree as $v):
echo $customer_id = $v['customer_id'];
array_push($arr, $customer_id);
$this->make_tree($customer_id);
endforeach;
var_dump($arr);
}
But the var_dump($arr) and echo results output like:
1013
array
empty
array
0 => string '13' (length=2)
11
array
empty
array
0 => string '10' (length=2)
1 => string '11' (length=2)
How can I make a single array of all the three outputs, ie an array with elements 13,10,11

Answer 1

you need to send the array with the parameters otherwise a new array is created.
function make_tree($customer_id,$arr = array()){
$ctree = $this->customer_operations->view_customer_tree($customer_id);
foreach($ctree as $v):
echo $customer_id = $v['customer_id'];
array_push($arr, $customer_id);
$this->make_tree($customer_id, $arr);
endforeach;
var_dump($arr);
}
PS: I don't know what you are trying to do exactly, but you probably need to add a stopping condition that is going to return the final array, unless you want to pass it by reference.
UPDATE
Here is one way to do it:
function make_tree($customer_id, &$arr)
{
$ctree = $this->customer_operations->view_customer_tree($customer_id);
foreach($ctree as $v):
$customer_id = $v['customer_id'];
array_push($arr, $customer_id);
$this->make_tree($customer_id, $arr);
endforeach;
}
and this is how you'd use it:
$final_array = array();
make_tree($some_customer_id, $final_array);
// now the $final_array is populated with the tree data

Answer 2

You can use class scope.
class TheController {
private $arr = array();
function make_tree($customer_id){
$ctree = $this->customer_operations->view_customer_tree($customer_id);
foreach($ctree as $v) {
$customer_id = $v['customer_id'];
array_push($this->arr, $customer_id);
$this->make_tree($customer_id);
}
}
}