Introduction to Programming Lecture Notes PDF

Chapter 9-12 Computer Programming  Objectives Program and Programming Algorithms & Programs Software Life Cycle Computer Language Generations Flowchart  Program and Programming Program: A set of instruction written in a programming language that a computer can execute so that the mach...

Chapter 9-12 Computer Programming  Objectives Program and Programming Algorithms & Programs Software Life Cycle Computer Language Generations Flowchart  Program and Programming Program: A set of instruction written in a programming language that a computer can execute so that the machine acts in a predetermined way. Program solves a problem ‫البرنامج يحل مشكلة معينة‬ Before writing a program: – Have a thorough understanding of the problem – Carefully plan an approach for solving it. Programming: The Process of providing instructions to the computer that tells the processor what to do. 3  Algorithms and Programs An Algorithm is a solution to a problem that is independent of any programming language. While A program is an algorithm expressed using a specific set of instructions from any programming language. 4  Algorithm Example Maximum of two numbers Steps: 1.Read/input two numbers 2.Compare two numbers 3.Print the Greater number Average of three numbers Steps: 1.Read/input three numbers 2.Add three numbers 3. divide the sum by 3. 4.Print the result of divison 5 Software Life Cycle  Software Life Cycle What Requirements Gathering, Problem definition How Analysis and Design (Programming techniques) Do it Coding Test Testing Use Implementation and Maintenance 7  Computer Language generations Machine language ‫لغة اآللة‬ Assembly languages ‫لغة التجميع‬ High-level languages ‫لغة المستوى العالي‬ Very high-level languages ‫لغة المستوى العالي جدا‬ Natural languages ‫اللغات الطبيعية‬ 8  Machine Language Programs and memory locations are written in strings of 0s and 1s ‫أصفار وآحاد‬ Problems with machine languages ◼ Programs are difficult to write and debug ◼ Each computer has its own machine language Only option available to early programmers ‫كانت تستخدم في برمجة حاسبات الجيل‬ ‫األول‬ 9  Assembly Languages : ◼ For example, A for add, C for compare, etc. ◼ Use names rather than binary addresses for memory locations Require an assembler to translate the program into machine language Still used for programming chips and writing utility programs 10  High-Level Languages Transformed programming ◼ Programmers could focus on solving problems rather than manipulating hardware ◼ Programs could be written and debugged much more quickly Requires a compiler to convert the statements into machine language ◼ Each computer has its own version of a compiler for each language. 11  Very High-Level Languages Also called fourth-generation languages (4GLs) Considered nonprocedural languages ◼ The programmer specifies the desired results, and the language develops the solution ◼ Programmers can be about 10 times more productive using a fourth-generation language than a third-generation language 12  Natural Languages Resemble written or spoken English ◼ Programs can be written in a natural syntax, rather than in the syntax rules of a programming language The language translates the instructions into code the computer can execute 13 Major Programming Languages FORTRAN COBOL BASIC RPG Visual Basic C Java 14  Object-Oriented Languages C++ Java C# Visual Basic 15 Basic Translation Process Source program Link object file Process Check with standard preprocessor translation object files directives to unit for legal and other produce a syntax and object files to translation compile it into produce an unit an object file executable unit Executable Unit  A First Program - Greeting.cpp // Program: Display greetings Preprocessor // Author(s): Yehia EL Mashad directives // Date: 1/24/2012 Comments #include #include Provides simple access using namespace std; Function int main() { named cout y Less than < x< y Greater/equals >= x >= y Less than/equals > Width; Definition with initialization // Compute and insert the area float Area = Length * Width; Visual C++ IDE with Area.cpp Area.cpp Output #include #include using namespace std; int main() { Library header files cout > a >> b >> c; if ( (a != 0) && (b*b - 4*a*c > 0) ) { double radical = sqrt(b*b - 4*a*c); Invocation double root1 = (-b + radical) / (2*a); double root2 = (-b - radical) / (2*a); cout