More about Objects and Classes
Completion requirements
The relational operations on primitive data are ==, >=, <=, >, <, and !=. They compare two data values, when those values' type has an ordering. For example, integers are ordered by size or magnitude. The result of a relational operation is a boolean value: either True or False. The relational operators on objects like Strings are different, and they are expressed as methods. Pay special attention to the equality method, equals().
15. Review
Answer:
Exactly the same as the first version of it:
java.awt.Point[x=12,y=45]
java.awt.Point[x=-13,y=49]
You can not be sure about the internal workings of a program by inspecting its output!
Review
| Program: | What it did: |
|---|---|
| object, method changes state The first program | An object was constructed. The variable pt refers it. Then, new data replaced the old data inside the same object. |
| object, assignment replaces old The second program | An object was constructed. The variable pt refers it. Then, a new object was constructed with new data, and pt was changed to refer to the new object. The first object became garbage. |
Question 15:
When are two points equivalent?