Output of C Programs | Set 10

Predict the output of the below programs. 
Difficulty Level: Rookie
Question 1 

Output: 0 
There is no problem with the program. It simply creates a user defined type i and creates a variable a of type i.
Question 2 

Output: Compiler Error -> Initialization with incompatible pointer type. 
The line typedef int *i makes i as type int *. So, the declaration of a means a is pointer to a pointer. The Error message may be different on different compilers. 

One possible correct solution of this code is in Question 4.  Also now try this:

Question 3  

Output: Compiler Error -> Multiple Storage classes for a. 
In C, typedef is considered as a storage class. The Error message may be different on different compilers. 
Question 4 

Output: 
10 
Please write comments if you find any of the answers/explanations incorrect, or you want to share more information about the topics discussed above. 
References: 
https://eecs.uq.edu.au/ 
http://publib.boulder.ibm.com/infocenter/macxhelp/v6v81/index.jsp?topic=/com.ibm.vacpp6m.doc/language/ref/clrc03sc03.htm 
https://learn.microsoft.com/en-us/cpp/c-language/typedef-declarations?redirectedfrom=MSDN