CS IA: Procedural Programming CS IB: Object-Oriented Programming CS 13011 CS 13012 CS IA: Procedural Programming CS IB: Object-Oriented Programming

Where did C++ come from? BCPL was developed in 1967 as a language for writing operating systems and software compilers In 1970, the creators of UNIX operating system needed a high-level language that provided enough power and flexibility for their task. They developed B (a derivative of BCPL) In 1972, an enhanced and improved version of the language called C was used to code most of UNIX most of operating systems (one of the largest and most complicated pieces of software) is written in C or C++ source code for Microsoft Windows Vista contains 50 million lines of mostly C/C++ code source code Red Hat Linux v.7.1 contains 30 million lines of C/C++ code

The Birth of C++ C++ is an extension of C developed by Bjarne Stroustrup in early 1980s C/C++ are possibly the most popular programming languages in use today C++ absorbed the best features of C and made a few additions to make it even more powerful and convenient to use C was written to combine ease of high-level language with the power of low-level language with C it is very easy to write code that is difficult to understand and hard to debug one of the major additions introduced by C++ is the use of OBJECTS!

Hardware program - sequence of instructions to computer software - collection of programs hardware - physical devices that make up computer equipment computer - PC/mainframes/workstations computer contains 5 main components CPU - follows the instructions and performs calculations specified by the program input device - any device that allows outside world to communicate information to the computer output device - any device that allows computer to communicate information to the outside world main memory/primary memory/RAM - a list of addressable numbered memory locations that computer can operate upon bit - the least possible amount of information: 0 or 1 byte - 8 bits memory location - single (indivisible) portion of memory that holds data address - number that identifies a memory location secondary memory - memory that is used for keeping a permanent record of information - disks/data CDs/flash drives

Hardware Diagrams

Software program (again) - set of instructions for computer to follow system – to be used by other programmers operating system - allocates computer resources, launches other programs and makes sure they work properly libraries – collection of routines to be used in other programs: input/output, math application – to be used by end-users data - input to the program running/executing program - performing program instructions on given data languages natural - language used by humans high-level - language (close to natural) that is understood by humans, C++ is a high-level language low-level (assembly) - a list of instructions a computer can follow add X, Y, Z machine - list of instructions in binary format a computer understands 0101 0001 1100 0010 compiler - a system program that translates high-level language into low-level language code - source (high-level language), object (machine language) library - set of previously developed routines linker - program that takes object code, adds needed routines from libraries and produces executable code executable code - can run on computer

include files (add1.h, iostream) Software Cycle Diagam source code (add1.cpp) include files (add1.h, iostream) done by linker link object code with pre-compiled routines from standard libraries to produce executable code add include files check object code (add1.o) file unit for legal syntax and compile it into an object code standard libraries done by compiler executable code

C++ Program Layout #include <iostream> int main() { statement 1; include directive - tells compiler where to find certain items about the program main part (main function) - contain instructions for computer, starts and ends with braces: {} statement – single unit of execution each statement is ended with semicolon ; program consists of a sequence of statements comment is a portion of line ignored by compiler - serves to make the code easier to understand by humans breaks and indentation is for humans - compiler ignores them. Yet the program should be easy to read! #include <iostream> int main() { statement 1; // comment statement 2; ... }

First Program: helloWorld.cpp // displays a greeting // Mikhail Nesterenko // 8/25/2013 #include <iostream> using std::cout; using std::endl; int main() { cout << "Hello, World!" << endl; } preprocessor directive comments function named main() indicates start of program output statement

Rules of Programming syntax - the principles of constructing (structuring) the program semantics – the meaning of the program and its parts style – non-syntactic rules of program writing aimed at making program easier to read and understand