Bitrix: where on the Bitrix website can I read in detail about the $arSelect, $arResult, $arItem variables?

Question

1C-Bitrix

People! Please tell me where on the Bitrix website you can read in detail about the variables $arSelect, $arResult, $arItem?
I saw it somewhere on their website, I wanted to look deeper, but I can’t find it now ...
PS Sorry for such a banal question, I know how to google, I also tried searching on the developer portal / courses ..

Answer 1

Well, in general, there is no $arSelect variable as such, it's just a naming. Such variables are used to write sampling parameters when using the API. example
But $arResult, $arItem already belong to the template.
$arResult – an array of the results of the component's work. It’s written right in the documentary
About reading specifics somewhere - you are unlikely to find it, because the composition of the arrays will be different and it depends on the type of component and the set of parameters

Answer 2

This set of variables is not a standard, each developer names them at his own discretion. It is necessary to look at the logic of the code - it will become clear why they are needed in a specific place in the script.