Why is C# statically typed?

Question

I am a PHP web programmer who is trying to learn C#.

I would like to know why C# requires me to specify the data type when creating a variable.

Class         


        

Answer 1

Why do we need to know the data type before a class instance?

You don't! Read from right to left. You create the variable and then you store it in a type safe variable so you know what type that variable is for later use.

Consider the following snippet, it would be a nightmare to debug if you didn't receive the errors until runtime.

 void FunctionCalledVeryUnfrequently()
 {
   ClassA a = new ClassA();
   ClassB b = new ClassB();
   ClassA a2 = new ClassB(); //COMPILER ERROR(thank god)

   //100 lines of code

   DoStuffWithA(a);
   DoStuffWithA(b);      //COMPILER ERROR(thank god)
   DoStuffWithA(a2);
 }

When you'r thinking you can replace the new Class() with a number or a string and the syntax will make much more sense. The following example might be a bit verbose but might help to understand why it's designed the way it is.

   string s = "abc";
   string s2 = new string(new char[]{'a', 'b', 'c'});
   //Does exactly the same thing

   DoStuffWithAString("abc");
   DoStuffWithAString(new string(new char[]{'a', 'b', 'c'}));
   //Does exactly the same thing