csci 240

• int(integer)


  A - / + number between -2.1b and 2.1b
• unsigned int


  Exclusively non-negative number between 0 and 4.2b
• float & double


  Represent real numbers with decimal points, with the only difference being the amount of precision. Double is more
• char


  A single, ASCII character, usually represented by a value stored within a pair of SINGLE-quotes, e.g. 'a'
• string


  Effectively an array of character values
• bool


  A variable that contains ONLY true or false
• ifstream & ofstream


  For opening input/output files, respectively
• Anytime we declare variables or instantiate objects from a class, we always start with the data type of the variable, followed by the programmer-defined name
• cout is our "standard output stream" that we would print "stuff" to using the "output stream operator" or <<
• cin is our "standard input stream" that we would extract data from the user through the keyboard using the "input stream operator" >>
• endl and "\n" do the same thing: print a new line
• Conditional statements


  If-statements, if-else statements, switch statements
• Relational expressions evaluate to true or false
• The && (and) operator requires both relational expressions to evaluate to true for the result to be true
• The || (or) operator requires EITHER relational expression to evaluate to true for the result to be true
• == is the equality operator, = is the assignment operator
• Switch statements


  Great for testing for direct equality to a great number of potential outcomes or use-cases, the unique keyword is case
• Loop structures


  • for loop
  • while loop
  • do-while loop
• To utilize "random" numbers, we start with "seeding" our RNG or "random number generator"
• Arrays


  Allocate LOTS of variables all at once, the first element is always at index 0, the last legal index is at size - 1
• Manipulating arrays


  1. Iterate from start to finish

  2. Iterate in reverse order

  3. Access individual elements
• To find the mid-point of an array, we can use array[MAXIMUM_ARRAY_SIZE / 2]
• Calculating the average of an array

  1. Sum up all the elements

  2. Divide the sum by the number of elements
• The return 0; statement is commonly the "exit point" of the program
• How to open a file 


  #include <iostream>

  #include <fstream>

  int main() {

  // 1. Declare an object of type fstream.

  std::fstream file;

  // 2. Open the file using the open function.

  file.open(" file_name.txt ", std::ios::in);

  // 3. Check if the file is successfully opened.

  if (!file.is_open()) {

  std::err << "Unable to open file_name.txt";

  return 1;

  }

  // 4. File operations go here...

  // 5. Close the file using the close function.

  file.close();

  return 0;

  }
• Bool is true or false not true and false? Is this True or False

  True
• #include <iostream> 


  // cout, cin, endl
• #include <iomanip>


  fixed, setprecision, setw, left, right
• #include <fstream>


  ifstream, ofstream, fstream
• What is an example of a standard library?


  #include <iomanip>
• The values in array are equal to 7

    for ( int i = 0 ; i < MAXIMUM_ARRAY_SIZE ; i++ )  {    if ( array[i] = 7 )      cout << "This value is equal to 7." << endl;  }*/
• Before I can start generating random numbers, I have to seed my RNG first

  RNG or "random number generator"  srand( 33 ); // We can do this with a fixed value to ensure the same sequence of  // numbers are used
•   cout << rand() % 101 << endl; // Will generate random numbers in the range [0, 100]  cout << rand() % 61 + 15 << endl; // [15, 75]  cout << rand() / 61 << endl;What are the bounds of this code?

  (15 to 75)
• Integer variable


  Holds a numerical value
• String variable


  Holds text data
• slacker == 100
• myName == "Daniel"
• slacker > 0


  Slacker is positive
• slacker > 0 && (slacker % 30 == 0)


  Slacker is a positive value and a multiple of 30
• switch (slacker)


  1. case (0): slacker == 0

  2. default: This is the default statement