Stack vs heap in embedded context - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a local variable on the stack.

Embedded C

void func() {
    int [1] = 10;
}

Drag options to blanks, or click blank then click option'

Alocal_var

Bheap_var

Cglobal_var

Dstatic_var

Attempts:

3 left

💡 Hint

Common Mistakes

Using global or static variable names instead of local.

The variable local_var is declared inside the function and stored on the stack.

2fill in blank

medium

Complete the code to allocate memory dynamically on the heap.

Embedded C

int* ptr = (int*) [1](sizeof(int));

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Aalloc

Bmalloc

Cstackalloc

Dnew

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'new' which is C++ syntax, or 'alloc' which is incorrect.

malloc allocates memory on the heap in C.

3fill in blank

hard

Fix the error in the code to correctly free heap memory.

Embedded C

int* ptr = malloc(sizeof(int));
// ... use ptr
[1](ptr);

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Arelease

Bdelete

Cdispose

Dfree

Attempts:

3 left

💡 Hint

Common Mistakes

Using C++ keywords like 'delete' or incorrect functions like 'dispose'.

free releases memory allocated by malloc on the heap.

4fill in blank

hard

Fill both blanks to create a stack-allocated array and access its first element.

Embedded C

int arr[[1]];
arr[[2]] = 5;

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A10

B0

C5

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 as the first index or invalid array sizes.

The array size is 10, and the first element index is 0.

5fill in blank

hard

Fill all three blanks to allocate, assign, and free heap memory correctly.

Embedded C

int* ptr = [1](sizeof(int));
*ptr = [2];
[3](ptr);

Drag options to blanks, or click blank then click option'

Amalloc

B42

Cfree

Dnew

Attempts:

3 left

💡 Hint

Common Mistakes

Using C++ keywords or forgetting to free memory.

Use malloc to allocate, assign value 42, then free to release memory.