static void Main(string[] args) //Method name
{
//Write my c# Code !!!!
//System.out.printLn("some thing")
//CTRL + F5 => run without debug
//F5 => runs with debug
Console.WriteLine("this is the first project");
Console.WriteLine("this is the first project- second line");
//IntelliSense => to do the auto complete
//MVC and spring
//For calling another method in another class
TestClass testClass = new TestClass();
testClass.DoSomething();
//C# Keywords
// Modifier Keywords => abstract , new, sealed , partial
// Access Modifier keywords => public, private, internal, protected
// statement keywords => if else switch case do for while foreach try catch finally return
// Methods parametr keywords => ref out
// namespace keywords => using
// Type keywords => bool, byte, char, decimal, class, enum, float, long
string message = "My first app";
Console.WriteLine(message);
//you can have access to both public classes
SalaryCalculate salaryCalculate = new SalaryCalculate();
salaryCalculate.Calc();
Student student1 = new Student(1, "TOTO", "A");
Student student2 = new Student(2, "POPO", "B");
float a = 10f / 3;
Console.WriteLine(a);
double b = 10d / 3;
Console.WriteLine(b);
decimal c = 10m / 3;
Console.WriteLine(c);
Test test = new Test();
test.testEnum();
//call by value and call by reference
//calling by value does not change the original after return
Console.WriteLine("-----------------Call by value -------------");
int x = 100;
Console.WriteLine("before calling the method the value of x {0}", x);
ChangeValue(x);
Console.WriteLine("after calling the method the value of x {0}", x);
//Call by reference
Console.WriteLine("call by reference");
x = 100; //imagine the address of x is 0x60000
Console.WriteLine("before calling the method the value of x {0}", x);
ChangeValueByRef(ref x); //I will pass &0x60000 => it means the address of x
Console.WriteLine("after calling the method the value of x {0}", x);
//Classes are using call by reference
Stud std1 = new Stud();
std1.name = "John";
ChangeName(std1);//I passed the reference
Console.WriteLine(std1.name);
//casting
double doubleNumber = 123.7;
int intNumber;
int g = 123456;
//implicit casting
long l = g;
//explicit casting
intNumber = (int)doubleNumber;
Console.WriteLine(intNumber);
//Casting of classes
Monkey monkey = new Monkey();
//Implicit conversion to base type is safe!
Animal animal = monkey;
//animal.sound() is not acceptable
// Explicit Conversion is required to
// cast back to the derived type
Monkey monkey2 = (Monkey)animal;
Elephant elephant = new Elephant();
Animal animal2 = elephant;
//I don't have any compile time error
//this casting can throw exception
//at run-time if the right side
//is not a monkey in fact!!!
//this code will be throws invalid cast exception
//Monkey monkey3 = (Monkey)animal2;
//this code is safe because it does type checking
if (animal2 is Monkey)
{
Monkey monkey3 = (Monkey)animal2;
}
else if (animal2 is Elephant)
{
Elephant elephant2 = (Elephant)animal2;
}
}
static void ChangeName(Stud c)
{
//It will change the original data
c.name = "Bill";
}
