What types of objects can be in a data stack?

In a data stack (stack), primitive data types and references to objects are usually stored, but not the objects themselves. In Android and Java, objects are placed in the heap, while the stack stores the addresses of these objects and local variables.

Thus, the stack can contain:

• Local variables of primitive types (int, boolean, float, etc.)
• References to objects

Example:

void method() {
    int a = 10; // stored in the stack
    MyObject obj = new MyObject(); // obj is a reference in the stack, the object is in the heap
}