Unit 1: Primitive Types

  • primitive: int, double, boolean
    • variable store data
  • import scanner to add user input
  • +: addition symbol
    • used to add two numbers.
  • -: subtraction symbol
    • used to subtract two numbers.
  • *: multiplication symbol
    • used to multiply two numbers.
  • /: division symbol
    • used to divide two numbers.
  • %: modulo operator
    • used to find the remainder of the division of two numbers.
  • compound operators
    • a = a + 1 same as a += 1 or age ++

  • casting to change between different data types

  • used in calculating the price of a car

    • add different features with different prices
  • getting on highway 2 cars at a time
    • total cars gotten on highway is car += 2
  • casting can be used for estimates
    • take the true speed of the car as double round to int to show driver without too much confusion/too many numbers

Unit 2: Using Objects

  • objects: reference types
    • reference to stored data
  • class: defines object
  • constructor: makes the data that will be stored in object
  • method made up of five parts: the scope, the return type, the name, the parameters, the body
    • scope: public/private - who can access code
    • return type: void (nothing is returned)
    • name: name of method
    • parameters: what is added to the constructor (the data)
    • body: what the method does
  • math class
    • abs(int a): absolute value of the argument as an int or double, depending on whether you put in an int or double into the argument
    • pow(double a, double b): value of a raised to the power of b as a double
    • sqrt(double a): square root of the argument as a double
    • random(): s a random number between 0 (inclusive) and 1 (exclusive) as a double
  • constructor that creates different features to be stores in an objects
    • Car(String brand, String model, int year) Car flash = new Car("BMW", "X7", 2023);
  • use math class find acceleration - positive or negative