comp104 notes

Class Test Date(s): Wednesday, 17/12/2014 Time: 10:00-12:00 Room: BROD-305

ELEC431 LECTURE INTRODUCTION TO C/C++

L1

Content What is C++  Why C++  Generation form and feature of C++  Programme style  Data type  I/O 

What is C++?  

C++ is a programming language. A computer program performs a specific task, and may interact with the user and the computer hardware.  Human work model:

 Computer

work model:

What is C++? 



The most popular programming languages:  Basic (Beginner All-purpose Symbolic Instructional Code)  C++ (an object-oriented language, based on C)  Fortran (FORmula TRANslation)  Java  Pascal (named for Blaise Pascal)  Visual Basic (Basic-like visual language developed by Microsoft)  C (developed by the designer of the B language) The most common versions of C++:  Microsoft VC++  Eclipse  g++ (for Unix machines)

Why C++? 

Bad News:  C++ is not easy to learn

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Good News:  Lots of good-paying jobs for programmers because C++ is not easy to learn!  Java uses C++ syntax, it is easy to learn Java if you know C++.  Though C++ is not the easiest language (Basic and Pascal are easier), it is not the hardest either (Prolog and Assembly languages are really difficult!)

Who Uses C++?   

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Computer makers such as Sun, SGI, IBM, and HP Airport Computer chip manufacturers like Motorola & Intel Software companies Banks Government Hospital Authority Telecommunications Universities

Most Important Feature of C++ 

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Most important feature of C++: its strong and efficient support of both Structured Programming and Object-Oriented Programming. C++ runs on:  PC  Macintosh  Unix workstations (also, Unix versions of C++ are free!)  supercomputers

Computer Software Relationships User Interface Application Programs

User Interface

Operating System

User Basic Input and Output Services (BIOS) Interface • needed for a computer to boot up

Computer Hardware

Introduction to C++ 

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 

C is a programming language developed in the 1970's alongside the UNIX operating system. C provides a comprehensive set of features for handling a wide variety of applications, such as systems development and scientific computation. C++ is an “extension” of the C language, in that most C programs are also C++ programs. C++, as opposed to C, supports “objectoriented programming.”

General form of a C++ program // Program description #include directives int main() { constant declarations variable declarations executable statements return 0; }

C++ keywords     

Keywords appear in blue in Visual C++. Each keyword has a predefined purpose in the language. Do not use keywords as variable and constant names!! Common keywords: bool, break, case, char, const, continue, do, default, double, else, extern, false, float, for, if, int, long, namespace, return, short, static, struct, switch, typedef, true, unsigned, void, while

Example – adding 2 numbers        

Peter: Hey Frank, I just learned how to add two numbers together. Frank: Cool! Peter : Give me the first number. Frank: 2. Peter : Ok, and give me the second number. Frank: 5. Peter : Ok, here's the answer: 2 + 5 = 7. Frank: Wow! You are amazing!

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after Frank says “2”, Peter has to keep this number in his mind.

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after Frank says “5”, Peter also needs to keep this number in his mind. First number: 2

Second number: 5

Sum:

7

The Corresponding C++ Program #include using namespace std; int main() { int first, second, sum; cout