INTRODUCTION T.Najah Al_Subaie Kingdom of Saudi Arabia Prince Norah bint Abdul Rahman University College of Computer Since and Information System CS240

Instructor: Najah AL-Subaie Course URL: Text Book:  C++ How to Program, DETITEL & DEITEL, eighth Edition  C++ Without Fear A Biggener's Guide That Makes You Feel Smart, Brian Overland

Course Syllabus Topics Introduction Data types, variables, values, assignment Sequence, iteration, branching statements Functions Arrays Pointers and Strings Recursion

Course Objectives  Learn data types, control structures, functions, and arrays.  Learn algorithms and problem-solving.  Learn analysis of problems using structured programming.  Learn program correctness and verification.  Learn the mechanics of running, testing, and debugging

Grading  2 Midterms : 25%  Project: 5%  Lab work : 10%  Final exam: 40%  Final lab: 20%  Bonus: +5 Marks (Pop quizzes)

Our first Question !!  What are the differences between hardware and software?!!  Computer hardware is any physical device (e.g. the computer monitor), something that you are able to touch and software (e.g. Internet browser) is a collection of instructions and code installed into the computer and cannot be touched.  What is the relation between SW and HW??  Software (Instruction) controls hardware (computer).

Programming Languages  Machine Language  The only language computer directly understands  Generally consists of 0s and 1s:  It is difficult to understand by humans.  To calculate wages= rates * hours in machine language: // Load //Multiply //Store

Programming Languages  Assembly language  English-like abbreviations to represent computer operations.  Clearer to humans.  Incomprehensible to computers.  Assemblers : convert program to machine language. Machine LanguageAssembly Language LOAD STOR MULT ADD

Programming Languages  High-level language  Similar to everyday language.  Uses common mathematical notations.  Clearer to humans.  Incomprehensible to computers.  (compilers): convert program to machine language.  The equation: wages= rate * hours written in C++: Wages=rate * hours;

Basics of C++ Environment  C++ programs typically go through six phases to be executed.  Edit: Programmer types a C++ program.  Preprocess: e.g. include other text files to be compiled.  Compile: translate the C++ program into machine language code.  Link: links the code with the code for the missing functions.  Load: load the executable code on memory.  Execute: CPU executes the program one instruction at time.

Structure of a program Output

Structure of a Program Cont. // my first program in C++  This is a comment line.  All lines beginning with two slash signs (//) are considered comments and do not have any effect on the behavior of the program.  The programmer can use them to include short explanations or observations within the source code itself.  In this case, the line is a brief description of what our program is.

Structure of a Program Cont. #include  Lines beginning with a hash sign (#) are directives for the preprocessor.  The directive #include tells the preprocessor to include the iostream standard file.  This specific file (iostream) includes the declarations of the basic standard input-output library in C++,

Structure of a Program Cont. using namespace std;  All the elements of the standard C++ library are declared within what is called a namespace, the namespace with the name std.  So in order to access its functionality we declare with this expression that we will be using these entities. This line is very frequent in C++ programs that use the standard library.

Structure of a Program Cont. int main ()  This line corresponds to the beginning of the definition of the main function.  The main function is the point by where all C++ programs start their execution.  int in the left, indicates that main “return” an integer.  The word main is followed in the code by a pair of parentheses ().  Right after these parentheses we can find the body of the main function enclosed in braces {}. What is contained within these braces is what the function does when it is executed.

Structure of a Program Cont. cout << "Hello World!";  This line is a C++ statement.  A statement is a simple or compound expression.  cout is the name of the standard output stream in C++.  The meaning of this statement is to print “ Hello World!” on the screen.  The semicolon (;) is used to mark the end of the statement.  Semicolon must be included at the end of all expression statements in all C++.

Structure of a Program Cont. return 0;  The return statement causes the main function to finish.  It indicate that the program ended successfully.