42_cpp00

First exercise of the C++ module at 42 Berlin

style notes

I want to use a style which is different than the one used in the C module.

• The format of the comments is doxygen compatible
• the braces are on the same line as the function name or the control structure.
• no namespaces are allowed as per in the subject.

The use of endl

One of the differences to C is the use of endl instead of \n. Also std::cout is a "stream" and std::endl is a manipulator that not only inserts a new line but also flushes the output buffer.

The toupper function

toupper is a c function also directly avalaible in cpp without using namespaces. It converts a lowercase char to uppercase. In C++ 98 there are not many other alternatives. I did not see in this case a "proper" c++ way of getting a string uppercase. There are possible variations of this using transform but I cannot use them because the subject forbid the use of the STL for this exercise.

Use of pragma once and #if guards

to avoid double inclusion of header files we can use either this syntax:

#ifndef HEADER_HPP
#define HEADER_HPP
// code
#endif

or

#pragma once

The second one is more modern and is supported by most compilers but it is not standard. Some codebases use both to ensure compatibility with older compilers.

Use whichever you prefer but be consistent.

ex00

Simple program that prints a string in uppercase in a c++ way. To find the c++ was probably more challenging than the actual implementation.

ex01

Create a contact book with 8 entries and a basic menu to interact with it. I can ADD, SEARCH and EXIT.

ex02

It is a kind of puzzle in c++. the file Account.hpp and the tests.cpp was given. We had to create the file Account.cpp and implement the methods. The output had to be the same as the log file given in the subject. For this assignment I actually also did create some tests in the tests folder which compare my output to the one in the subject.

Explanation of Code in tests.cpp Ex02

In the "Account.hpp" file, both pragma once and #if guards are used for compatibility. the Account class is defined with a typedef for t like typedef Account t; which is probably for conciveness. The main function in tests.cpp has a few other typedefs:

	typedef std::vector<Account::t>							  accounts_t;
	typedef std::vector<int>								  ints_t;
	typedef std::pair<accounts_t::iterator, ints_t::iterator> acc_int_t;

It seems that they want us to see some real cpp code in action. So accounts_t is a vector of Account::t (where t is an alias for Account again). ints_t is a vector of integers. acc_int_t is a pair of iterators, one for accounts_t and one for ints_t, facilitating simultaneous iteration over accounts and transaction amounts. The rest of the code is about initializing account and transaction data, and printing the account information before and after the transactions.

tests

to run the tests you can use the following command:

make 
make -C tests

Debug

I use a debug macro in the code. To enable it you can uncomment this line in the makefile:

# CXXFLAGS += -DNDEBUG

It is just a simple macro that prints the file and the line where it was called.

#ifdef NDEBUG
#define debug(...)
#else
#define debug(msg) \
    std::cerr << COLOR << __FILE__ << ":" << __LINE__ << ": " << msg << RESET << std::endl;
#endif

It is nice to be able to switch on and off the debug statements.

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