Programming principles

• A computer is a programmable device that stores and processes data
• Electronic devices accept data as input, process that data, produce output, and store the results
• A computer is not intelligent; it cannot analyze a problem and come up with a solution
• A human (the programmer) must analyze the problem, develop the instructions for solving the problem, and then have the computer carry out the instructions
• Advantages of using computers:

  • Computers can repeat a solution very quickly and consistently once it's been written
  • Computers free people from repetitive and boring tasks
• To write a program for a computer to follow, a two-phase process is required: problem-solving and implementation
• Problem-solving phase:

  • Analyze
  • General Solution (Algorithm)
  • Test
• Implementation Phase:

  • Specific Solution (Program)
  • Test
  • Maintenance
• Identifiers in programming:

  • Variable names and class names are examples of identifiers
  • Choose names for variables that give an indication of their purpose
  • Rules for identifiers:
  • First character: a-z, A-Z, underscore "_", or dollar sign "$"
  • After the first character: a-z, A-Z, underscore "_", dollar sign "$", and digits 0-9
  • No spaces allowed
  • Uppercase and lowercase characters are distinct
• Variable and Class names:

  • Start variable names with a lowercase letter
  • Start class names with an uppercase letter
  • Each subsequent word's first letter must be capitalized
• Primitive Data Types:

  • Variables are classified according to their data type
  • Data type determines the kind of data that may be stored, memory usage, and data formatting
  • Examples of primitive data types:
  • byte, short, int, long, float, double, char
• Primitive Data Types:

  • Data Types: byte, short, int, long, float, double, char
  • Memory Size and Range for each data type provided
• Primitive Data Types ranking:

  • double
  • float
  • long
  • int
  • short
  • byte
  • Highest rank to lowest rank
• The Integer Data Types:

  • Variables declared as a certain type
  • Values assigned to variables
  • Example code snippet demonstrating the use of integer data types
• The Floating-Point Data Types:

  • Include float and double
  • Floating-point literals are assumed to be of the double data type unless suffixed with "F" to force it to be treated as a float
• The boolean Data Type:

  • Allows variables to hold true or false values
  • Useful for evaluating conditions that are either true or false
• The char Data Type:

  • Used to store characters
  • Can hold only one character at a time
• Characters in C# are internally represented by numbers, with each character assigned a unique number
• C# uses Unicode, a set of numbers used as codes for representing characters
• Each Unicode number requires two bytes of memory, so char variables occupy two bytes
• In C#, characters can be assigned using their Unicode numbers
• Arithmetic operators in C# include: addition, subtraction, multiplication, division, and modulus
• Addition operator in C# returns the sum of its two operands
• Subtraction operator in C# returns the value of its right operand subtracted from its left operand
• Division operator in C# returns the quotient of its left operand divided by its right operand
• Multiplication operator in C# returns the product of its two operands
• Modulus operator in C# returns the remainder of a division operation involving two integers
• Integer division in C# results in an integer when both operands are integers
• For a division operation to return a floating-point value in C#, one of the operands must be of a floating-point data type
• Combined assignment operators in C# provide a faster way to perform arithmetic operations and assignment
• C# automatically converts lower-ranked data types to higher-ranked data types in assignment statements
• Three ways to comment in C# are: single-line comments (//), multi-line comments (/*...*/), and documentation comments (///)
• Boolean logic is used in nearly every programming language
• Boolean logic allows the translation of real-world problems into computer code
• C, C++, and C# are three different computer programming languages that use similar syntax with operators like and, or, and not represented by different symbols
• Gates are devices that perform basic operations on electrical signals
• Gates accept one or more input signals and produce a single output signal
• There are six fundamental types of gates: NOT, AND, OR, XOR, NAND, and NOR
• Boolean algebra allows only two values: 0 and 1
• A truth table defines the function of a gate by listing all possible input combinations and their corresponding outputs