The Call Stack and Scope

Topics: Stack, scope Expected length: $1$ hour

How to diagram the call stack:

$1.$ Start with main

a$.$ Walk through each line of code

b$.$ Diagram memory for each variable as it is declared

c$.$ Modify variables values as needed

$2.$ When a function is called

a$.$ Add a stack frame for that function

b$.$ Place the parameters and values in the function stack frame

c$.$ Walk through each line of code in the function, adding and modifying variables

$3.$ When the last line of the function is reached, return to main, crossing off the stack frame for the function.

a$.$ Remember to record any returned values in main

$4.$ Continue until the end of main is reached.

Note: Once a function is finished running, it is no longer present on the call stack. You can simply not draw it or cross it out if you$$ve already drawn it$.$