Object-Oriented Programming: Using real life situations to create a model to solve a problem

Object-Oriented Programming: Using real life situations to create a model to solve a problem

1. Java object: has attributes (fields) and performs actions (methods)

   • Java objects represent real-world objects but with less details
     • To assign a created object with an object variable: Ex: Employee employee = new Employee();
     • To call an objects methods or fields: objectReference.methodName objectReference.fieldName

2. Java class: a tempate to create objects of similar types

   • Syntax for a class: class className { [class body] }
     • Each word in a class name is capitalized. ex: Employee, DateUtility
     • Class file must be saved as className.java

3. Fields: variables that are primitive or references to other objects

   • Should follow camel naming convention. Ex: age, maxAge

4. Methods: actions that an object can take

   • Method declaration contains a return value, method name, and list of arguments
     • Declaration syntax: returnType methodName {listofArguments}
     • Return type void means that the method returns nothing
     • ex: Address getAddress() // returns an address object
   • Constructor method: Constructs the object and does not have a return value
     • The compiler will add one for you if not defined

5. "main" provides the entry point to the application

   • Syntax for the main class: public static void main {String[] args}