oop - Can an instance variable belong to multiple classes? -

i have been looking @ classes in oop , curious how works.

for example, lets have product. product bike.

there class product stock , class products details e.g. colour etc.

i use classes within each other such class called product , within it contains both stock , details product(bike)

or have instance called bike made both

e.g.

stock bike = new stock(); details bike = new details();

or instance bike have renamed them e.g.

stock stockbike = new stock(); details detailsbike = new details();

hopefully makes sense. wondered whether 1 instance keyword can belong 2 classes or instance name in case bike have changed can belong more classes.

thanks

stock bike = new stock(); details bike = new details();

not quite sure you're asking... think you're asking if can have 2 variables same name , in same scope. generally, no. didn't mention language let's assume java.

public void test() {    string test = "123";    string test = "123";  // error    integer test = 123;  // error     stock bike = new stock();    details bike = new details();  // error } 

one case have same name... although discouraged... local variable same name , type variable of higher scope

public class test {    private string mystring;     ...     public void test() {        string mystring = "123";  // warning , discouraged     } }