递归cURL函数php

Question

I am having a problem with a php function, it is a recursive function - which seems to work, because if i dump the array I see the items are added to the array. But when I want to return the array I get a null.

The api function is a http curl wrapper function which handles the api call - that works fine, also the $arr get's filled with the db_address items - but the return doesn't return the array - if I var_dump the result I get a Null, if I print_r the result I just get a 1.

function get_all_db_addresses($arr, $skip){
if(!isset($arr)){
    $arr = [];
}
if(!isset($skip)){
    $skip = 0;
}
$db_addresses = json_decode(db_api('GET', 'DbAddress?$skip=' . $skip), true);
$arr = array_merge($arr, $db_addresses['value']);
if(!array_key_exists('@odata.nextLink', $db_addresses)){
    return $arr;
} else {
    $skip += 20;
    get_all_db_addresses($arr, $skip);
}
}

Am i doing something wrong here? I don't see what i'm doing wrong here..

Answer 1

You have 2 problems:

1. You don't have return statement when performing recursive call
2. In case you perform array_merge with null, you will get null

Check this:

function get_all_db_addresses($arr = array(), $skip = 0)
{
    $db_addresses = json_decode(db_api('GET', 'DbAddress?$skip=' . $skip), true);
    if (isset($db_addresses['value'])) {
        $arr = array_merge($arr, $db_addresses['value']);
    }
    if (array_key_exists('@odata.nextLink', $db_addresses)) {
        return get_all_db_addresses($arr, $skip + 20);
    }
    return $arr;
}