Trouble finding answer to professor imposed questions

I've read over the chapters where the topics of covered and am still left with a couple questions. If you guys wouldn't mind setting me straight, I'd appreciate it.

What 3 things happens when this is executed

Code:

---

throw class1();

---

and

Code:

---

catch(...);

---

What happens when this is executed?

Code:

---

class1();

---

Or this?

Code:

---

throw a;

---

Or this?

Code:

---

catch (int i)

---

You are refering to what is know as exception handeling. This paticular mechanism, called try-catch, is found in many popular languages. It is made up of the two blocks, the try blocks and catch blocks. Try basically executes code in block and looks to see if an excpetion is trhown. An exeption is any error that occurs in the program. To let the try know if an expetion occured you use a throw statment such as

throw exception;

This is were the catch block comes into play. It is the part that actually deals with the exception. When a try trhows an exception, it immedially haults execution of anything after the throw statement and jumps to the catch block. What you write inside of the catch block to deal with the error is left up to you.