static void Main(string[] args)
{
SomeOperation add = Sum;
int result = add(10, 10);
Console.WriteLine(result);
Func <int, int, int> addFunc = Sum;
result = addFunc(10, 10);
Console.WriteLine(result);
Func <int> getRandomNumber = delegate()
{
Random rnd = new Random();
return(rnd.Next(1, 100));
};
Console.WriteLine("Random number: " + getRandomNumber());
Func <int> getRndNumber = () => new Random().Next(1, 100);
Console.WriteLine("Random number: " + getRndNumber());
Func <int, int, int> Suma = (x, y) => x + y;
Console.WriteLine("Sum = " + Suma(12, 23));
}
static void Main(string[] args)
{
SomeOperation add = Sum;
int result = add(10, 10);
Console.WriteLine(result);
}
static void Main(string[] args)
{
SomeOperation add = new SomeOperation(Sum); // sau mai puteam SomeOperation add=Sum;
int result = add(10, 20);
Console.WriteLine(result);
Func <int, int, int> adauga = Sum;
int rezultat = adauga(32, 21);
Console.WriteLine(rezultat);
//Func with Anonymous Method
Func <int> RandomNumber = delegate()
{
Random random = new Random();
return(random.Next(1, 100));
};
var r = RandomNumber;
int an = r();
Console.WriteLine("Random Number " + r); //System.Func`1[System.Int32]
Console.WriteLine("Random Number1 " + an);
//Func with lambda expression
Func <int> getRandomNumber = () => new Random().Next(1, 100);
var a = getRandomNumber;
Console.WriteLine("Random Number2: " + a());
//Or Func with lambda expression 2
Func <int, int, int> Suma = (x, y) => x + y;
int b = Suma(12, 14);
Func <string, int, string[]> extractMeth = delegate(string s, int i)
{
char[] delimiters = new char[] { ' ' };
return(i > 0 ? s.Split(delimiters, i) : s.Split(delimiters));
};
string title = "The Scarlet Letter";
// Use Func instance to call ExtractWords method and display result
foreach (string word in extractMeth(title, 2))
{
Console.WriteLine(word);
}
foreach (string word in extractMeth(title, 4))
{
Console.WriteLine(word);
}
}
public static void Calculate(int choice, double numOne, double numTwo)
{
IDictionary <int, string> allActionsDictionary = new Dictionary <int, string>()
{
{ 1, "adding" },
{ 2, "subtracting" },
{ 3, "multiplying" },
{ 4, "dividing" }
};
switch (choice)
{
case 1:
{
SomeOperation addNumbers = Delegate.Add;
var result = addNumbers(numOne, numTwo);
ShowTheResults.Show(allActionsDictionary[1], numOne, numTwo, result);
break;
}
case 2:
{
SomeOperation subtractNumbers = Delegate.Subtract;
var result = subtractNumbers(numOne, numTwo);
ShowTheResults.Show(allActionsDictionary[2], numOne, numTwo, result);
break;
}
case 3:
{
SomeOperation multiplyNumbers = Delegate.Multiply;
var result = multiplyNumbers(numOne, numTwo);
ShowTheResults.Show(allActionsDictionary[3], numOne, numTwo, result);
break;
}
case 4:
{
SomeOperation divideNumbers = Delegate.Divide;
var result = divideNumbers(numOne, numTwo);
ShowTheResults.Show(allActionsDictionary[4], numOne, numTwo, result);
break;
}
default:
{
Console.WriteLine("There is no such a method!");
break;
}
}
}
public static void Calculate(int choice, double numOne, double numTwo)
{
switch (choice)
{
case 1:
{
SomeOperation addNumbers = Delegate.Add;
var result = addNumbers(numOne, numTwo);
ShowTheResults.Show("adding", numOne, numTwo, result);
break;
}
case 2:
{
SomeOperation subtractNumbers = Delegate.Subtract;
var result = subtractNumbers(numOne, numTwo);
ShowTheResults.Show("subtracting", numOne, numTwo, result);
break;
}
case 3:
{
SomeOperation multiplyNumbers = Delegate.Multiply;
var result = multiplyNumbers(numOne, numTwo);
ShowTheResults.Show("multiplying", numOne, numTwo, result);
break;
}
case 4:
{
SomeOperation divideNumbers = Delegate.Divide;
var result = divideNumbers(numOne, numTwo);
ShowTheResults.Show("dividing", numOne, numTwo, result);
break;
}
default:
{
Console.WriteLine("There is no such a method!");
break;
}
}
}
private static void Functions()
{
SomeOperation add = Sum;
int result = add(10, 10);
Console.WriteLine(result);
Func <int, int, int> add2 = Sum;
var result2 = add2(1, 2);
Func <int, int, int> add3 = delegate(int a, int b) { return(a + b); };
Func <int, int, int> add4 = (int a, int b) => { return(a + b); };
Func <int, int, int> add5 = (a, b) => { return(a + b); };
Func <int, int, double> division = (a, b) => { return((double)a / b); };
}
static void Main(string[] args)
{
#region Info
/*
* - C# includes built-in generic delegate types Func, Action and Predicate, so that you don't need to define custom delegates
* - Predicate is built-in delegate type defined in the System namespace
* - Predicate delegate has one input parameters and one out parameter
* - Predicate delegate must return a bool value
* - Predicate delegate can be used with an anonymous method or lambda expression
*/
#endregion
SomeOperation del1 = IsUpperCase;
Console.WriteLine($"del1 - IsUpperCase(UP) = {del1("UP")}");
Predicate <string> predDel1 = IsUpperCase;
Console.WriteLine($"predDel1 - IsUpperCase(Up) = {predDel1("Up")}");
SomeOperation del2 = IsPalindrom;
Console.WriteLine(del2("Madam"));
Console.ReadLine();
}
//Func is built-in delegate type.
//Func delegate type must return a value.
//Func delegate type can have zero to 16 input parameters.
//Func delegate does not allow ref and out parameters.
//Func delegate type can be used with an anonymous method or lambda expression.
static void Main(string[] args)
{
SomeOperation add = Sum;
int result = add(2, 3);
Console.WriteLine(result);
Func <int, int, int> add_v2 = Sum;
int result_2 = add_v2(10, 20);
Console.WriteLine(result_2);
Func <int> getRandomNumber = delegate()
{
Random rnd = new Random();
return(rnd.Next(1, 100));
};
Console.WriteLine(getRandomNumber.Invoke());
Func <int> getRandomNumber_2 = () => new Random().Next(1, 100);
Console.WriteLine(getRandomNumber_2.Invoke());
Func <int, int, int> sum = (x, y) => x + y;
Console.WriteLine(sum.Invoke(200, 300));
Func <int, int, int, DateTime> createDateTime = (day, month, year) => new DateTime(year, month, day);
Console.WriteLine(createDateTime(1, 9, 2019));
}
