C# course 2

  1. Funkcje w C# – weird syntax, but works:
 //funkcja generuje 30 liczb losowych
    public static int[] ScanTest()
        var answers = new int[30];

        Random random = new Random();

        for (int i = 0; i < answers.Length; i++)
            answers[i] = random.Next(0, 2);

        return answers;

    //funkcja zliczajaca sume wszystkich skladnikow tablicy
    public static double CalculateScore(int[] answers)
        int sum = 0;

        for (int i=0;i<answers.Length;i++)
            sum += answers[i];

        double score = (double)sum / answers.Length;

        return score;

2. Classes and objects

Class – it is like schema or template

Object – indivdual of chosen class (like presentation in PowerPoint acc. to chosen PowerPoint template;))

3. How to define class:

namespace ConsoleApp2
class Student

//here are defined fields


//getters and setters

//here are defined methods



3. fields and setters and getters

a) old fashioned way – public field

public string StudentNumber; //field without getter and setter...in object you can set it like that: obj.StudentNumber="1";
b) simplified getters and setters
    public string StudentNumber2 { get; set; } //getters and setters generated in such a simple way!!! ... in bject used in the same way as above

c) getters and setters in oldfashioned way – like in Java

private int _test;

    public int getTest()
        return _test;

    public void setTest(int value)
        _test = value;

d) getters and setters with conditions (great!) .It returns boolean value on the basis of float value

public bool HasScholarship
if (Grade>4.5)
return true;
return false; 

Another example:

      private double _grade;
        //inny rodzaj setera i gettera (warunkowy)
        public double Grade
            get { return _grade;   }

                if (value<=5.0)
                    _grade = value;

4. constructors

a) default constructor

//konstruktor domyslny
public Student()

b) constructor with parameters

//konstruktor z argumentami
        public Student(string studentNumberabcd,double grade)
            StudentNumber = studentNumberabcd;
            Grade = grade;


        public Student(string studentNumber)
            StudentNumber = studentNumber;

5. references – how to compare 2 objects and why „==” is not good;)

Student normalStudent = new Student("123456",3.4);
Student normalStudent2 = new Student("123456", 3.4);
//te obiekty nie sa sobie rowne - sprawdzane jest miejsce w pamieci;)
Console.WriteLine(normalStudent == normalStudent2);
        //kiedy to bedzie prawda
        Student normalStudent3 = normalStudent2;
        Console.WriteLine(normalStudent3 == normalStudent2);

        //jak wlasciwie powinno sie porownywac dwa obiekty?

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