Messages and Methods - Java for COBOL Programmers - page 58

would produce
Hello World!
null
This println statement causes the text null to appear in the output window.
On the other hand, the version of ErrorMsg in the exercises initialized the
msgText data member to one space. Therefore, these statements
System.out.println ("HelloWorld!");
tempMsg = myErrorMsg.getErrorMsg ();
System.out.println (tempMsg);
Hello World!
cause a single space character to appear in the output window (which is invisible).
The HelloWorld application then stores some text, in this instance, of ErrorMsg .
HelloWorld uses the setErrorMsg method to store this text.
myErrorMsg.setErrorMsg ("Some Text");
HelloWorld next gets the text item from ErrorMsg and prints out the contents of
this data member. Note that the output for this statement is the text “Some Text.”
tempMsg = myErrorMsg.getErrorMsg ();
System.out.println (tempMsg);
Some Text
Next, HelloWorld modifies the data member and prints out its new contents.
In this case, the output for this print statement is the text “Some New Text.”
myErrorMsg.setErrorMsg ("Some New Text");
tempMsg = myErrorMsg.getErrorMsg ();
System.out.println (tempMsg);
Some New Text
Finally, you modified HelloWorld to create a second instance of ErrorMsg and
stored a reference to this new instance in the variable myErrorMsg2 . You then stored
the String “Some Text for #2” in its data member, using the setErrorMsg method: