C++ Programming - Basic Elements (Part C)

C++ Programming - Basic Elements (Part C)

• Putting data into variables:
  • Variables receive data using assignment statements (like variable = expression;) or input statements (using cin).
  • Interactive input involves the user typing data, which the computer receives from the keyboard.
  • Input statements use cin >> variable1 >> variable2, which get data from the standard input.
  • Example: cin >> miles; reads input and stores it in the variable miles.
  • Example: cout << "Please insert the value of miles: "; prompts the user for input
  • Example: double miles; declares a variable miles of type double.
• Assignment statements:
  • The basic form is variable = expression;.
  • Variables on the left side get the value calculated on the right side of the equation.
  • Example: int counter = 5; declares and initializes a variable counter to 5.
• Input (read) statements (using cin):
  • cin >> variable reads input from the user and assigns it to the variable. Spaces, tabs, or returns act as separators.
  • Example: cin >> feet >> inches; reads two integers separated by a space.
  • Using getline to read strings: getline(cin, name); reads the entire line entered by the user, which is now stored in string variable name. Use this for names, or multiple words. This function correctly handles multiple words in a single line of input.
  • Example (when reading a string including multiple words): cout << "Please enter your name: "; getline(cin, name); cout << "Your name is: " << name << endl;

Increment and Decrement Operators

• Increment operators (++) increase a variable's value by 1.
  • counter++; is the post-increment operator (increments after the expression is evaluated).
  • ++counter; is the pre-increment operator (increments before the expression is evaluated).
• Decrement operators (--) decrease a variable's value by 1.
  • counter--; (post-decrement)
  • --counter; (pre-decrement)
• These operators can be used within expressions and calculations, impacting variable values in different ways.

Example usage

• Example code demonstrates the correct use of cin and cout to prompt the user and get data from the command line.