C#: أساسيات الطريقة

access_modifier return_type method_name(parameter_list)
{
    method_body
}

using System;

class Program
{
    static void SayHello()
    {
        Console.WriteLine("Hello, World!");
    }

    static void Main()
    {
        SayHello();
        SayHello();
    }
}

Hello, World!
Hello, World!

using System;

class Program
{
    static void Greet(string name)
    {
        Console.WriteLine("Hello, " + name + "!");
    }

    static void Main()
    {
        Greet("Alice");
        Greet("Bob");
    }
}

Hello, Alice!
Hello, Bob!

using System;

class Program
{
    static int Add(int a, int b)
    {
        return a + b;
    }

    static void Main()
    {
        int result = Add(3, 5);
        Console.WriteLine("3 + 5 = " + result);
        Console.WriteLine("10 + 20 = " + Add(10, 20));
    }
}

3 + 5 = 8
10 + 20 = 30

using System;

class Program
{
    static string GetGrade(int score)
    {
        if (score >= 90)
            return "Excellent";
        if (score >= 60)
            return "Pass";
        return "Fail";
    }

    static int Max(int a, int b)
    {
        if (a > b)
            return a;
        else
            return b;
    }

    static void Main()
    {
        Console.WriteLine(GetGrade(95));
        Console.WriteLine(GetGrade(70));
        Console.WriteLine(GetGrade(45));
        Console.WriteLine("Larger: " + Max(12, 8));
    }
}

Excellent
Pass
Fail
Larger: 12

using System;

class Program
{
    static void PrintLine(int length)
    {
        if (length <= 0)
            return;
        string line = new string('-', length);
        Console.WriteLine(line);
    }

    static void PrintInfo(string name, int age)
    {
        Console.WriteLine("Name: " + name);
        Console.WriteLine("Age: " + age);
    }

    static void Main()
    {
        PrintInfo("Alice", 18);
        PrintLine(20);
        PrintLine(-5);
    }
}

Name: Alice
Age: 18
--------------------

using System;

class Program
{
    static int Square(int x)
    {
        return x * x;
    }

    static int SumOfSquares(int a, int b)
    {
        int sa = Square(a);
        int sb = Square(b);
        return sa + sb;
    }

    static void Main()
    {
        int result = SumOfSquares(3, 4);
        Console.WriteLine("Result: " + result);
    }
}

Result: 25

1. Main() pushed onto stack
2.   SumOfSquares(3, 4) pushed onto stack
3.     Square(3) pushed → returns 9 → popped
4.     Square(4) pushed → returns 16 → popped
5.   SumOfSquares returns 25 → popped
6. Main → outputs 25 → popped

using System;

class Program
{
    static double CalculateArea(double radius)
    {
        return 3.14159 * radius * radius;
    }

    static bool IsValidAge(int age)
    {
        return age >= 0 && age <= 150;
    }

    static void PrintUserInfo(string name, int age)
    {
        Console.WriteLine(name + ", age " + age);
    }

    static void Main()
    {
        double area = CalculateArea(5.0);
        Console.WriteLine("Area: " + area);
        Console.WriteLine("Valid age: " + IsValidAge(25));
        PrintUserInfo("Alice", 25);
    }
}

Area: 78.53975
Valid age: True
Alice, age 25

using System;

class Program
{
    static int Square(int x) => x * x;

    static double CircleArea(double r) => 3.14159 * r * r;

    static bool IsAdult(int age) => age >= 18;

    static void Main()
    {
        Console.WriteLine(Square(7));
        Console.WriteLine(CircleArea(3.0));
        Console.WriteLine(IsAdult(20));
    }
}

49
28.27431
True

using System;

class Program
{
    static void TryChange(int x)
    {
        x = 999;
    }

    static void Main()
    {
        int num = 10;
        TryChange(num);
        Console.WriteLine("num = " + num);
    }
}

num = 10

using System;

class Program
{
    static int GetLength(string text)
    {
        return text.Length;
    }

    static double GetAverage(int a, int b)
    {
        return (a + b) / 2.0;
    }

    static bool IsPositive(double value)
    {
        return value > 0;
    }

    static string BuildGreeting(string name)
    {
        return "Welcome, " + name + "!";
    }

    static void Main()
    {
        Console.WriteLine(GetLength("Hello"));
        Console.WriteLine(GetAverage(3, 4));
        Console.WriteLine(IsPositive(-2.5));
        Console.WriteLine(BuildGreeting("Alice"));
    }
}

5
3.5
False
Welcome, Alice!