Technology Fundamentals
Call Stack
Definition
In computer science, a call stack is a stack data structure that stores information about the active subroutines (functions) of a computer program. It is used to keep track of the point to which each active subroutine should return control when it finishes executing.
Why It Matters
The call stack is fundamental to how almost all programs execute. It manages the flow of control, passing parameters to functions and returning values from them. Debuggers use it to trace the path of execution.
Contextual Example
If function `A` calls function `B`, and `B` calls function `C`, the call stack will have `A` at the bottom, then `B`, then `C` at the top. When `C` finishes, it's popped off the stack and control returns to `B`.
Common Misunderstandings
- A "stack trace" or "stack dump" is a report of the active stack frames at a certain point in time, which is extremely useful for debugging when a program crashes.
- A "stack overflow" error occurs when the call stack runs out of memory.