Monitoring Program Memory Usage

While you can't check memory usage directly from within C++, there are several tools and techniques you can use to monitor how much memory your program is using.

Task Manager (Windows)

The simplest way on Windows is to use Task Manager:

1. Run your program
2. Press Ctrl+Shift+Esc to open Task Manager
3. Look for your program in the list
4. Check the "Memory" column

Activity Monitor (Mac)

On Mac, you can use Activity Monitor:

1. Open Activity Monitor from Applications > Utilities
2. Look for your program
3. Check the "Memory" column

Visual Studio Memory Usage Tool

If you're using Visual Studio:

1. Run your program in debug mode (F5)
2. Open Debug > Windows > Memory Usage
3. This shows detailed information about memory usage

Here's a simple program that uses different amounts of memory. Try running it and watching the memory usage in Task Manager:

1#include <iostream>
2#include <string>
3using namespace std;
4
5int main() {
6  cout << "Press Enter to continue each"
7    " step...\n\n";
8
9  string input;
10  getline(cin, input);
11
12  // Create some variables that use memory
13  int32_t Numbers[10000];
14  cout << "Created array of 10000 integers\n";
15
16  getline(cin, input);
17
18  // Create more variables
19  int32_t MoreNumbers[100000];
20  cout << "Created array of 100000 integers\n";
21
22  getline(cin, input);
23
24  cout << "Program ending...";
25}

The program pauses between allocations so you can watch the memory usage increase in Task Manager. Remember that the total memory used will be more than just our variables - the program itself needs some memory to run!

While these tools can help you track memory usage, the best way to manage memory is to think about it while writing your code. Use appropriate types for your data, and avoid creating unnecessary variables or really large arrays unless you need them.