Basic C++ lectures 1 and 2MSc Bioinformatics Basic C++

Basic C++ lectures 1 and 2MSc Bioinformatics Introduction Daniel Soto phone: address:Departament de Tecnologia Desp.374 Estació de França Passeig de Circumval·lació, Barcelona

Basic C++ lectures 1 and 2MSc Bioinformatics Introduction  Philosophy: learn to program with objects  Bibliography The C++ Programming Language, 3rd Edition by Bjarne Stroustrup. Addison Wesley Professional. “Aprenda C++ como si estuviera en primero” manualcpp.pdf

Basic C++ lectures 1 and 2MSc Bioinformatics Programming Languages Machine Languages Assembly Languages High-Level Languages LOAD A ADD B STORE C C=A+B

Basic C++ lectures 1 and 2MSc Bioinformatics Programming paradigms  Imperative  Declarative  Functional  Object-Oriented

Basic C++ lectures 1 and 2MSc Bioinformatics Evolution of High-Level Programming Languages  Functions and Methods  Libraries (packages, units, etc.)  Abstract Data Types  Objects

Basic C++ lectures 1 and 2MSc Bioinformatics C++ language  History  1980, creation of different flavours of “C with Classes”  1983, C++ evolution from C with inspiration in Simula67  1991, ANSI C++  C++ vs. C C was chosen as the base language for C++ because it:  is versatile, terse, and relatively low-level;  is adequate for most systems programming tasks;  runs everywhere and on everything; and  fits into the UNIX programming environment.

Basic C++ lectures 1 and 2MSc Bioinformatics C++ language  What is C++? C++ is a general-purpose programming language with a bias towards systems programming that:  is a better C,  supports data abstraction,  supports object-oriented programming, and  supports generic programming. C is retained as a subset inside C++ (this is not completely true!)

Basic C++ lectures 1 and 2MSc Bioinformatics C++ language  First program (C-style): #include int main() { printf("Hello world!\n"); } ;  First program (Pure C++-style): #include int main() { std::cout << "Hello world!\n"; } ;

Basic C++ lectures 1 and 2MSc Bioinformatics Compilation hello.o compile a.out a.exe hello.cpp C++ runtime Link Source FileObject FileExecutable Edit g++ hello.cpp

Basic C++ lectures 1 and 2MSc Bioinformatics C/C++ Compatibility  General:  C++ provides the // comments // a comment return a; // another comment  C Code that is not C++:  Functions in C++ have strict syntax main() {} // Valid in C, not valid in C++ int main() {;} // Valid in C++  Default types not assumed const a=7; // In C is type int, not in C++  Several new keywords in C++:  class, this, throw, public, protected, private, virtual, true, false, template, inline, friend, new …

Basic C++ lectures 1 and 2MSc Bioinformatics Summary  C++ is a evolution of C. We can continue to use C syntax. Formal variations exist. We need to use a different compiler and new file extension. A new programming paradigm is integrated into it.

Basic C++ lectures 1 and 2MSc Bioinformatics Summary  The paradigm of Object-Oriented Programming

Basic C++ lectures 1 and 2MSc Bioinformatics OOP: Objective  Say to a machine what it need to do (using objects).  In general this is programming

Basic C++ lectures 1 and 2MSc Bioinformatics OOP: approach  We can view a program as a “object”  This object is the medium to do work using a machine A

Basic C++ lectures 1 and 2MSc Bioinformatics OOP: approach  Is the Object-Oriented Programming a thing like…  Cooking programs with objects?

Basic C++ lectures 1 and 2MSc Bioinformatics OOP: approach  Create programs with pieces?  Work with programs?

Basic C++ lectures 1 and 2MSc Bioinformatics OOP: concepts  Object: a mix of data and procedures  Abstraction: view only a partial view of a thing  Message interchange: how to object delegates a task to other object  Class: the model of the object  Instance: one agent (the object)  Heritage: How to an object is a “derivate” from another object  Polymorphism: Different views of the same object