COMP 1000: Think Like a Computer: The PreTeXt Interactive Edition

Traditionally, the first program written in a new language is called Hello, World! because all it does is display the words, Hello, World! In Python, the source code looks like this.

print("Hello, World!")

This is an example of using the print function, which doesn’t actually print anything on paper. It displays a value on the screen, in the programming console. Programmers do their work in development environments (software applications designed specifically for developing programs). In a development environment there is typically one part of the window where the programmer edits the program, and another part of the window, called the console, where output (such as from a print statement) is displayed. The ActiveCode panel is like our development environment. In this case, the result on the console is the phrase:

Hello, World!

Here is the example in an ActiveCode window, where you can run it and modify it. When you click the Save & Run button, a grey console window appears below the ActiveCode window. That is where output from print() statements will always appear.

The quotation marks in the program mark the beginning and end of the string value. They don’t appear in the result. You’ll learn more about why in the next chapter.

Some people judge the quality of a programming language by the simplicity of the Hello, World! program. By this standard, Python does about as well as possible.

For comparison in another language, the Hello, World! program in Java looks like this:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}