CSC 2.3 S2

• Basic Data Type and Declaration

  1. Integer
  2. Floating point
  3. Double
  4. Character
  5. String
  6. Boolean
• Data type: int

  Size: 4 bytes

  Description: Stores whole numbers, without decimals
• Data type: float

  Size: 4 bytes

  Stores fractional numbers, containing 7 decimal digits
• Data type: double

  Size: 8 bytes

  Stores fractional numbers, containing 15 decimal digits
• Data type: Boolean

  Size: 1 byte

  Stores true or false values
• Data type: char

  Size: 1 byte

  Stores a single character/letter/number
• #include <iostream> using namespace std; int main () { int myNum = 1000;

  cout << myNum; return 0; }
• #include <iostream> using namespace std; int main () { float myNum = 5.75; cout << myNum; return 0; }
• #include <iostream> using namespace std; int main () { double myNum = 19.99; cout << myNum; return 0; }
• #include <iostream> using namespace std; int main () { char myGrade = 'B'; cout << myGrade; return 0; }
• STRING

  #include <iostream> #include <string> using namespace std;

  int main() {

  string greeting = "Hello";

  cout << greeting;

  return 0; }
• #include <iostream> using namespace std; int main() { bool isCodingFun = true; bool isFishTasty = false;

  cout << isCodingFun << "\n";

  cout << isFishTasty;

  return 0; }

  OUTPUT:

  1

  0
• Punctuation symbols: , . : ; ? !
• Parentheses: ()

  Braces: {}

  Brackets: []
• Quotation marks: " '
• Variable: Data type + VariableName

  Example: int x, y;

  float radius;

  char gred;
• IDENTIFIER : Combination of letters (both uppercase and lowercase), digits and the underscore ()
• IDENTIFIER: underscore

  Data-1 : invalid

  M_6 : valid
• IDENTIFIER: The first character must be a letter or an underscore the rest of the name can be letter, digit or an underscore
• IDENTIFIER: first letter

  _City or City: valid

  17numbers: invalid
• IDENTIFIER: Blank space is not allowed
• IDENTIFIER: no blank space

  Student_age : valid

  Student age : invalid
• KEYWORD : Must be typed fully in lower case
• Keyword example: while, return, float, char, dll
• ESCAPE SEQUENCE : The backslash (\) is called escape character
• \n : new line
• \t : horizontal tab
• \" : double quote
• \' : single quote
• \\ : Backslash to print a backslash character
• \? : Question mark
• Constant

  1. Char
  2. String
  3. Int
  4. Float
  5. Double
• INTEGER CONSTANT • Positive or negative whole numbers with no fractional part

  7550 : valid

  3.44 : invalid
• INTEGER CONSTANT

  Consists of an optional plus (+) or a minus (-) sign

  -15 : valid

  0179 : invalid
• INTEGER CONSTANT Has no comma or other special character

  +250 : valid

  1,899 : invalid
• INTEGER CONSTANT

  const int x = 7;
• CHARACTER CONSTANT

  A single character enclosed in single quotation marks
• CHARACTER CONSTANT

  const char category = 'A';
• FLOATING POINT CONSTANT Positive or negative decimal numbers with an integer part, a decimal point and a fractional part
• FLOATING POINT CONSTANT

  const float gov_tax 2.5;