Test MDX File V4

This is a Test MDX File for my Code Output setup for Code Cloze and Code Output.

Testing Code Cloze Example.

A component with gaps in the source code and decoy pills. Added a “reset” option when the answers are incorrect as it’s difficult to drag snippets back to the pool.

Code Cloze

C++

Complete the Hello World Program

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Drag snippets from the pool into the blanks so the program produces the output shown, then click Submit.

1#include <·····>

2using namespace ·····;

3

4int main() {

5 ····· << "Hello, world!";

6 return ·····;

7}

Expected Output

Hello, world!

Available Snippets

iostream

printf

cout

System

std

stdio.h

NULL

0

void

Submit

Predicting Program Output

These exercises ask you to read a short snippet and choose the terminal output it produces.

Knowledge Check

Here is a Code Output exercise (C++), expanded by default … example division example. Note the output uses \n to place code on different lines. No syntax highlighting possible.

Code Output

C++

Integer Division vs. Floating Point

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Read the code below, then choose the terminal output it produces and click Submit.

1#include <iostream>

2using namespace std;

3

4int main() {

5 int a = 7;

6 int b = 2;

7 cout << a / b << endl;

8 cout << (double)a / b << endl;

9 return 0;

10}

stdout

3.5
3.5

stdout

3
3

stdout

3
3.5

stdout

3.5
3

Submit Answer

Here is a Code Output exercise (Rust), collapsed by default … The && is a little complex in the closure (pointer to pointer!) for the filter method. The initial code exposed the correct answer automatically when an incorrect answer was chosen. This version tracks incorrect answers.

Code Output

Rust

Iterator Chain Output

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Bitwise Lab…

Lab: Bitwise Operations on 8-bit unsigned int (uint8_t)

Click bits on A and B, choose an operation, and the result updates live.

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Bit #

7

6

5

4

3

2

1

0

dec / hex

A

0001

1001

250x19

B

0000

0101

50x05

A = 25 0x19B = 5 0x05

Textbook valuesRandomiseClearAll 1s

A & BBitwise AND

1 only where both bits are 1 — used to mask / clear bits

A

0

0

0

1

1

0

0

1

250x19

B

0

0

0

0

0

1

0

1

50x05

A & B

0

0

0

0

0

0

0

1

10x01

Try this:Click Textbook values to load A=25, B=5 and step through each operation to match the chapter's output table. Then try A & B with B set to 0000 1111 to isolate the low nibble of A — a classic masking idiom.

Interactive Memory Lab

The lab below is pre-loaded with the textbook example: float a = 25.0;, int b = 545;, and double c = 123.0;. Drag any type from the palette onto the memory strip to allocate it. Click a placed variable to rename it or change its value.

C++ Memory Lab

Drag a type onto memory and watch the variable claim the bytes its size demands.

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Memorybase = 0x1000

16 / 16 bytes used0 free

+0

+4

+8

+C

×

a

25.0

×

b

545

×

c

123.0

byte 0

4

8

12

Type Palette — drag onto memory

Textbook exampleClear memory

bool8-bit

char8-bit

short16-bit

int32-bit

unsigned int32-bit

long64-bit

unsigned long64-bit

float32-bit

double64-bit

integer types

floating point

character

boolean

Declared variables

Type	Name	Value	Address	Size
float	a	25.0	0x1000 – 0x1003	4 bytes (32-bit)
int	b	545	0x1004 – 0x1007	4 bytes (32-bit)
double	c	123.0	0x1008 – 0x100F	8 bytes (64-bit)

Try this:Click Textbook example to load a, b, c. Then drag a char onto memory — notice it claims a single byte, same as a bool, while double claims eight. Click any placed variable to rename it or change its value. With 16 bytes of memory there's no room for all five textbook variables at once — that's the point: char and bool are cheap, double is expensive.

End Tests…