Create function inside function to send e-mail - php

Question

I have a problem with functions. I create functions to send e-mails. I'm trying to create function, for example: I call function with variable ($product_id), and depends on this product id, I would like to send e-mails.
<?php
$product_id = 2000;
echo select_users_to_send($product_id);
function get_product_type($id_product){
// Define product group
global $wpdb;
$sql = "SELECT n_products.Product_Group
FROM tsales_funnel_mrecord
LEFT JOIN n_products on tsales_funnel_mrecord.Product_type = n_products.Product_Code
WHERE ID = $id_product";
$type_product = $wpdb->get_var($sql);
return $type_product;
}
function select_users_to_send($type = get_product_type($product_id)){
return $type.' user';
}
?>
I wrote this code, but it didn't works for me. Shows error:
Parse error: syntax error, unexpected '(', expecting ')'
Maybe there need to use classes? But I didn't understand how to write classes.

Answer 1

try this
function select_users_to_send($product_id){
$type = get_product_type($product_id)
return $type.' user';
}

Answer 2

Try this:
This code solved the error "Parse error: syntax error, unexpected '(',
expecting ')'"
<?php
$product_id = 2000;
echo select_users_to_send($product_id);
function get_product_type($id_product){
// Define product group
global $wpdb;
$sql = "SELECT n_products.Product_Group
FROM tsales_funnel_mrecord
LEFT JOIN n_products on tsales_funnel_mrecord.Product_type = n_products.Product_Code
WHERE ID = $id_product";
$type_product = $wpdb->get_var($sql);
return $type_product;
}
// getting output from the function
$type = get_product_type($product_id);
// passing the $type var
function select_users_to_send($type){
return $type.' user';
}
?>

Answer 3

You can create class like this. But You can solved your issue using first answer, This is only example for your knowledge for classes
select_user.php
class select_user{
# Start function get_product_type
function get_product_type($id_product){
// Define product group
global $wpdb;
$sql = "SELECT n_products.Product_Group
FROM tsales_funnel_mrecord
LEFT JOIN n_products on tsales_funnel_mrecord.Product_type = n_products.Product_Code
WHERE ID = $id_product";
$type_product = $wpdb->get_var($sql);
return $type_product;
}
# Start function select_users_to_send
function select_users_to_send($product_id){
$type = get_product_type($product_id);
return $type.' user';
}
}# End Class
Now create PHP file for call to class
# include class file path
include ('select_user.php');
# create class object
$user_create = new select_user();
# Call methord of class class_name
$product_id = 2000;
$return_val = $user_create->select_users_to_send($product_id);
echo $return_val;