Allocation of memory to variables on the stack

On this page

Memory allocation overview
Allocation of memory to variables
Why do the size of objects stored on the stack must be known at compile-time?
What's problematic about Problematic()?
Limitations we've observed of the stack
Questions

This lesson contains approximately 32 minutes of video content.

Memory allocation overview

Allocation of memory to variables

Why do the size of objects stored on the stack must be known at compile-time?

What's problematic about Problematic()?

Limitations we've observed of the stack

Questions

QAMVS Q0

This question is ungraded.

Where do named objects (not declared as static/global) have their memory allocated?

Code/static region.

Free store.

Heap.

Stack.

Practice question: try as many times as you like

QAMVS Q1

This question is ungraded.

In the video, we define the function Fact recursively. Given our definition of Fact, invoking Fact(3) will cause how many activation records for Fact to be pushed to the stack?

Practice question: try as many times as you like

QAMVS Q2

This question is ungraded.

In the video, we explicitly state that you can think of the stack as a

growing and shrinking array of heterogeneous objects.

growing and shrinking array of homogeneous objects.

list of heterogeneous objects.

stack of vinyl records.

Practice question: try as many times as you like

QAMVS Q3

This question is ungraded.

The following code introduces a variable-length array (VLA) on the stack:

int size = 0; 
std::cin >> size;
int array[size];

Is this code valid per the C++ standard?

No, since the code will not compile on any modern C++ compiler.

No, the C++ standard states that the compiler must know a stack array's size at compile time.

Yes, variable-length arrays are valid in the C99 standard.

Yes, variable-length stack arrays are valid per the C++98 standard.

Practice question: try as many times as you like

QAMVS Q4

This question is ungraded.

Given the following function,

char* GetString(std::istream& is) {
  char str[255];
  is >> str;
  return str;
}

what's wrong with GetString's definition?

A pointer to an array cannot be returned by _any_ function.

An array's name can _never_ be used to initialize a pointer.

The address of stack memory associated with a local variable is returned.

The return type must be `char&` instead of `char*` for `GetString` to compile.

Practice question: try as many times as you like

QAMVS Q5

This question is ungraded.

What memory region allows us to create an object in a function and have that object's lifetime extend beyond that function?

Code region.

Free store.

Stack.

Static region.

Practice question: try as many times as you like