Where in memory are primitive data types stored in Java?

In Java, primitive data types (e.g., int, boolean, char, double) are stored on the stack when declared locally within methods. This is because the stack is intended for storing local variables and method calls.

If primitives are fields of an object, they are stored on the heap along with the object itself.

Thus:

• Local primitives are on the stack.
• Primitives as object fields are on the heap.

Example:

public class Example {
    int field; // stored on the heap with the object

    public void method() {
        int localVar = 10; // stored on the stack
    }
}