Comments

Lesson

In python, try executing the following code:

Displays "I love yogurts" on the terminal
print("I love yogurts")

It displays an error, because the language doesn’t recognize what you wrote as valid instructions.

Now, try executing this:

# Displays "I love running" on the terminal
print("I love running")

It works, and the line with the # is ignored.
This is called a comment, and is useful to… comment your code.
It is useful for others to understand your code, but also for yourself if you check back at your code in the future.

In other languages

Comments are usually done with #, // or /* */.
Usually, to comment a line, # is used in Python, // in other languages.
To comment multiples lines, in most languages, you can wrap your code between /* and */.

In C++:

#include <iostream>

int main() 
{
    // Displays "I love running" on the terminal
    std::cout << "I love running" << std::endl;

    /* This is 
        a comment 
        that takes
        multiple lines.*/

    /* This one 
     * takes multiple
     * linest too.
     */
}