This simulation has two modules:

1. Call By Value
2. Call By Reference

Open the simulation page and click the thumbnail of the module you want to run.

Steps for Call By Value

1. Click Start to begin execution.
2. Observe the first highlighted code line in the Program Code panel.
3. Click Next to move to the next execution step.
4. At each step, observe all three panels together:
   • Program Code: currently executing line is highlighted.
   • Memory Map: addresses and stored byte values are updated.
   • Code Output / Explanation: printed output and reasoning for that step.
5. Continue clicking Next to trace declaration of A, declaration of pointer P, assignment P = &A, dereferencing *P, and update of A through pointer.
6. Use Back to revisit previous steps and verify how values and addresses change in reverse order.
7. Continue until program execution completes; the simulation resets to initial state for a fresh run.

Steps for Call By Reference

1. Click Start to begin execution.
2. Click Next to step through main() and the function call to swap(&A, &B).
3. Observe pointer variables in the swap function (Pa, Pb) and the temporary variable (temp) in the Memory Map.
4. Track how dereferencing updates original values:
   • temp = *Pa
   • *Pa = *Pb
   • *Pb = temp
5. Compare Code Output before and after swap to confirm that values of A and B are exchanged in caller memory.
6. Use Back to inspect reverse flow and confirm each intermediate memory state.
7. Run till completion to see final swapped values and automatic reset.

What to Verify During Simulation

1. Every variable occupies a memory address.
2. A pointer stores an address, and dereferencing accesses/modifies value at that address.
3. Passing addresses to a function allows modification of original variables (call by reference behavior).

Note for Mobile Users:

This simulation is optimized for desktop computers with larger screens and mouse interaction. If you access this experiment on a mobile device, please rotate your device to landscape mode for the best experience. Some features may be limited or harder to use on small screens.