Push an array within an array - php

Question

I created a function called "keyword_query()" which gets a single string and runs a query with this variable on an API - then the API returns an array (which is defined global so it's changed outside the function too).
The second function "keyword_query_array()" should run the "keyword_query()" more than once, and push to a new array (which is global too) and get an array of several arrays. This function gets a variable of an array of keywords. The function gets the array and navigates through the array without any problem.
Please notice the comments in the code:
<?php
// Runs the query "Research Key" on a keyword and get App ids, names, ect'.
function keyword_query($keyword){
global $research_key_array, $keyword;
// Add the keyword to the "Research Key" query:
$research_key_query = "https://example.com/api/banana/ajax/kaka?term=$keyword&country=US&auth_token=666";
// Create a stream for Json. That's how the code knows what to expect to get.
$context_opts = array(
'http' => array(
'method' => "GET",
'header' => "Accepts: application/json\r\n"
)
);
$context = stream_context_create($context_opts);
// Get the Json
$research_key_json = file_get_contents($research_key_query, false, $context);
// Turn Json to a PHP array
$research_key_array = json_decode($research_key_json, true);
//var_dump($research_key_array);
//print_r($research_key_array);
return $research_key_array;
}
// Runs the keyword_query() function on an array of keywords.
function keyword_query_array($keyword_array){
global $array_of_key_queries;
// Get the last array cell
$last_array_cell = count($keyword_array);
// Navigate through the array
for ($i=0; $i<=$last_array_cell ; $i++) {
//echo $keyword_array[$i]; ****works!
// Error here: Notice: Undefined offset: 3 in C:\wamp\www\PHPExcel\api_fun.php on line 51
array_push( $array_of_key_queries, keyword_query($keyword_array[$i]) );
}
var_dump($array_of_key_queries);
}
But when I get to this line:
array_push( $array_of_key_queries, keyword_query($keyword_array[$i]) ); I get an error of:
Notice: Undefined offset: 3 in C:\wamp\www\PHPExcel\api_fun.php on line 51
with this var_dump:
array (size=4)
0 =>
array (size=1)
'keyword' =>
array (size=0)
empty
1 =>
array (size=1)
'keyword' =>
array (size=0)
empty
2 =>
array (size=1)
'keyword' =>
array (size=0)
empty
3 =>
array (size=1)
'keyword' =>
array (size=0)
empty
What is the right way to push an array within an array like this case?

Answer 1

I changed global $research_key_array, $keyword; from the first function to global $research_key_array;
Works great now!
Thanks #Adelphia !