This code then walked through its characters, printing each of them out to the terminal. When we want an object to print out, we ask the object itself to do the printing. The way in which an integer is printed is much different from the way a string is printed on the inside, but because we are just sending a message, we do not have to be aware of this. We tell it to printNl , and it prints itself out. In later chapters we will see a wide range of types of objects.
White space is ignored, except as it separates words.
An integer can be sent a number of messages in addition to just printing itself. The way that it does this, however, is a significant departure from a procedural language. This 16 object was then given the printNl message, and printed 16 on the terminal.