1 What is the difference between a class and an object What

1. What is the difference between a class and an object? What is “Unique Identity” in regards to objects?

2. What do we mean by the following statement: “The UML has syntax and semantics”? Are you free to interpret UML diagrams any way you please?

3. Is encapsulation the same thing as information hiding?

4. List the Systems Development Lifecycle Phases. Should we skip steps in the lifecycle?

5. What is a “swim lane” for an Activity Diagram? What are swim lanes used for? Must we use swim lanes (yes or no)?

Solution

1)class means in the context of oop and class refers to actual piece of code which is used to define the behaviour of any given class

and an object retains its identity even if some or all the values of variables it is necessary in applications but not applicapble in tuples of relational database.

2)firstly there is notation or concrete syntax this defines what shapes are allowed on the diagrams:rectangles,ovals,lines and a set of rules how these shapes combine and appear

3)more generally encapsulation refers to simply bundling the data with the operations on that data so you have a class encapsulating data and the methods for manupulating data.data hiding means it just provides a way to protect data from the outside world

4)1)Requirements

   2)analysis

    3)design

     4)coding

     5)testing

      6)Release and maintenance

5)swim lane is a visual element used in process flow diagrams,or flow charts, that visually distinguishes job sharing and responsibilites for sub process of a business process it is arranged horizontally or vertically. yes we should use it