Thread: Instances of classes

Here's another C++ question that I'm curious about. In Java you only use the new keyword to create an instance of a class but in C++ there are a few ways. You can use

1) MyClass *c = new MyClass();

which returns a pointer to an instance of MyClass and there is

2) MyClass c;

which puts the actual instance of the class in the variable c and then there is

3) MyClass *c;

Both 1 and 3 are pointers to the class... so what's the difference. I know that since the first was created with new you have to later delete it. Why do you need to do this?

When do I use which?

It does really depend on what you want to do with the instance. If you only want to acces the memory location where an instance of the class is, then obviously you use a pointer.

The second one, is just like declaring a 'int x' for example.

Hope this helps.

Can't you do the same thing with all of them?

Hmmm... it looks like I should be using the second one more often instead of 1. Coming from the Java community I naturally want to use the new keyword.

Thanks for the clarification