Program Development C# Programming January 30, 2007 Professor J. Sciame

Computer Aided Problem Solving Steps for Computer Aided Problem Solving: –Program Analysis and Specification –Algorithm Development –Program Coding –Program Execution and Testing –Program Maintenance

Program Analysis & Specification Determine: –Program Input –Program Output Specification = Input & Output Problems Encountered –Changing Values –Being too specific

Algorithm Development Algorithm = The formulation of a problem as a detailed sequence of simple steps. Algorithms are designed using three basic methods of control: –Sequential Control –Selection Control –Repetitive Control

Pseudocode Pseudocode is a mixture natural language and symbols, which include: –Mathematical Operators –Variable Names –Comments –Keywords –Indentation

Flowchart A graphical display of an algorithm. Uses: –Symbols –Flow lines Alternate - Top Down Design

Program Coding To express the algorithm in a programming language Concepts: –Syntax –Variables –Data Types Readability

Program Execution Write the program with the editor Include preprocessor codes Save and compile the program Link the program Load into memory Execute (Run)

Errors Syntax (or Compile Time) Run Time Logic

Program Maintenance Responsibilities: –Testing & Validation –Maintenance

Software Engineering The study of the use of the techniques used to solve problems Systems Analysts - Help in complex problems

Memory Concepts Variable names correspond to locations in memory All variables have: –a name –a type –a size –a value

Memory Concepts II The statement cin >> integer1 or x = a + b is called a destructive read-in. The statement cout << x is called a non- destructive read-out

Arithmetic Operators Addition + Subtraction - Multiplication * Division / Modulus %

Order of Operations Parentheses must be cleared. Exponentiation Multiplication or Division (left to right) Addition or Subtraction (left to right) In nested parentheses, the innermost parentheses are first, working out to the outermost set.

Equality and Relational Operators Equality –(x is equal to y) x = = y –(x is not equal to y) x != y Relational –(x is greater than y) x > y –(x is less than y) x < y –(x is greater than or equal to y) x > = y –(x is less than or equal to y) x < = y