Joshua's Thoughts

Week #1 of CIT-120, Introduction to Computer Science and Object Oriented Programming was mostly a review for me, but I did learn some great things about the transfer program I’m in, as well as a some Window’s development topics I wasn’t so familiar with.

Each week, I will try and a provide a summary of the notes for my class. If the class has anything to add, please feel free to drop a comment and add clarification.

Notes

• Object Oriented Programming (a case sensitive language)
  • Benefits
    • Ability to create own data types
    • OO (Object Oriented) approach reduces duplicity
  • Data Types
    • User Defined Data Types
      
      • A class is a user defined data type
      • A class is a complex data type
      • If a class is declared, you are creating an object
    • Trivial Data Types
      • Store only one piece of information
      • Types (the main ones): int, double, char, bool
        • int - holds whole numbers only
        • double - can share #’s with decimals
        • char - can store one character
        • unsigned - strictly positive
  • Color Highlighting in Visual Basic
    • Blue - keywords, such as data type declarations
    • Black - strings and values
    • Green - comments are in green

    cout << "Delta"; // cout is a stream object, cout (console output)

  • Library - someone elses code that you include. Take caution when including a library. Only include libraries that are essential to your code’s functionality.
    • Two ways to include a library
      • .h method - this is the professor’s preferred method as it results in a slightly smaller executable size
      • Namespace method
      • .cpp files are text only and header files end in .h
  • Operators and Operands
    • Mathematic Operators (+ - / % *)
    • “to Overload Operators” - making existing operators misbehave
    • Exp: 5 * 3, 5 and 3 are the operands and the * is the operator
    • Most operators are binary, they can act on two entities
    • Cascade - using more than one operator at a time
    • In this next example, 5 and 2 are the operands and / is the operator. Notice the result is an integer. That is because the two operands are also integers.

    cout << 5/2; // Returns 2

    • Notice that as soon as you introduce a “real” data type into the operation, the result changes.

    cout << 5.0/2; // Returns 2.5
    cout << 5/2.0 // Returns 2.5
    cout << 5.0/2.0 // Returns 2.5

    • Modular Operator - %
      • Works only with integers and gives you the remainder. This is a great way of finding out if a result is even or odd. If you divide a number and the remainder is zero, it is even.
      • Examples

      cout << 15%2; // Returns 1 (2*7 = 14 + 1 = 15)
      cout << n % 1 // A number (n) modulated by 1 is always ZERO
      cout << 5 % n; // Will crash if n is zero

    • Shortcut Operators
      • They are: +=, -=, /=, %=
      • Exp: x+=5, the same as x=5+x
  • Errors
    • Runtime - occurs during the run, depends on the input
    • Syntax error - Compiler error-developer error
    • Logical error - A logic error - something doesn’t work as expected even if it compiler
  • Strings and Escape Sequences
    • Anything between double quotes “is a string”
    • Escape sequences allow you to do something to the output that if left unescaped, the compiler would throw and error. Some of the more commons ones are:
      • \n = new line
      • \t = tab
      • \r = carriage return
      • \a = alert (make the machine beep)