How to write response to global variable from VK API?

Question

JavaScript

I have a clear problem with the scope, because I do not understand how to display the response in a global variable in order to use it further) I do not want to process data only inside the method function.
i = VK.api() - of course it doesn't work.

var i = 0;

VK.api('groups.getById', {group_id: 'live'}, function (r){
  i = r.response[0].id;
  return i;
});

alert(i); // например, не суть.

Answer 1

You have a problem with asynchrony.

var i = 0;

console.log(1, 'запрос отправляется')
VK.api('groups.getById', {group_id: 'live'}, function (r){
  i = r.response[0].id;
  console.log(4, i); // здесь сработает правильно, но только после ответа с сервера
  return i;
});

console.log(2, 'ответ на запрос еще не пришел, а вы уже пытаетесь использовать переменную i')
console.log(3, i); // выведет 0

UPD: about

i = VK.api() - of course it doesn't work.

You have return i;inside an anonymous function that is used as a callback parameter for VK.api()
What exactly returns VK.api() can be found in their source code or documentation. Maybe it doesn't return anything at all.