Visual Programming Lecture 4

Operator Precedence

Methods, Classes, Objects, Method Calls, Attributes, Properties Discuss the definitions of Methods, Classes, Objects, Method Calls, Attributes, Properties (Get Accessor and Set Accessor) Create GradeBook class with the following code and test it: Using system; Public class GradeBook { public void DisplayMessage() Console.WriteLine(“Welcome to the Grade Book!”); }

Declaring a Method with Parameter Using system; Public class GradeBook { public void DisplayMessage(string courseName) Course.WriteLine(“Welcome to the grade book for \n{0}!”, courseName); }

Testing GradeBook GradeBook myGradeBook = new GradeBook(); Console.WriteLine(“Please enter the course name: “); String nameOfCourse = Console.ReadLine(); Console.WriteLine(); myGradeBook.DisplayMessage(nameOfCourse);

Instance Variables and Properties Variables declared inside a method are called “local variables” Variables declared inside class but outside method body are called “instance variables” Each object of a class has its own instance of “instance variable” Modify the GradeBook class as shown on next slide Also discuss UML class diagram

UML Diagram

Public class GradeBook { Private string courseName; Public string CourseName get { return courseName; } set { courseName = value; } Public void DisplayMessage() console.WriteLine(“Welcome to the grade book for \n{0}!”, CourseName); }

Testing GradeBook GradeBook myGradeBook = new GradeBook(); Console.WriteLine(“Initial course name is : ‘{0}’\n”, myGradeBook.CourseName); Console.WriteLine(“Please enter the course name: “); myGradeBook.CourseName = Console.ReadLine(); Console.WriteLine(); myGradeBook.DisplayMessage();

Auto Implemented Properties and Constructors Public class GradeBook { public string CourseName { get; set; } public GradeBook (string name) CourseName = name; } public void DisplayMessage() Console.WriteLine(“Welcome to the grade book for \n{0}!”, CourseName);

Testing GradeBook { GradeBook gradeBook1 = new GradeBook(“C# Programming”); GradeBook gradeBook2 = new GradeBook(“Data Structure”); Console.WriteLine(“gradeBook1 course name is : {0}”, gradeBook1.CourseName); Console.WriteLine(“gradeBook2 course name is : {0}”, gradeBook2.CourseName); }