gistfile1.md

Quick Java Reference

JS => Java

Java Primitives	Same as JavaScript	Access Modifiers
boolean	Arithmatic Operators	Public - Open Access
byte (8 bits)	Boolean Operators	Private - Only accessible within class
char	Function/Method Invocations	Protected - Accessible within same package/classes in other packages
short (32bits)	Loops (for, while, do while)	Default(no need to set) - Accessible only within package
int (32 bits)	Switch Statements	--------------------------------------------------------------------
long (64bits)	If-else-if conditionals	--------------------------------------------------------------------
float (32 bits)	Ternary Statement	--------------------------------------------------------------------
double(64bits)	--------------------------------	--------------------------------------------------------------------

Compiling Java for runtime

javac <package>/*.java
jar cvfe <name>.jar <package>.<main-class> <package>/*.class
java -jar <name>.jar

Casting

int three = (int) 3.14;

Logging

System.out.println(...)

Class Structure

public class Dog               <--- accesses modifier - "Class" - name of class
{
    private String breed;      <--- a class field(access modifier, data type, name) 
                               fields are pieces of data that classes hold in variables
                          
    private static int numberofDogs         <---- static field (means that its value is 
                                            the same across instances of class fields without 
                                            static can be unique for each instance of a class
                                    
    public Dog(String breed)                <--- constructor called with instantiating object instance of class
    {   
        this.breed = breed;                 <-- when an instance of Dog is created the constructor will set this 
                                                field to the data value passed in "this" is used to references 
                                                methods and fields attatched to the class
    }
    
    public String getBreed()                <-- class method 
                                            (access modifier, data type it returns, name, parameters(empty)
    {
        return this.breed;
    }

    public void setBreed(String breed)      <-- class method 
                                            returns nothing takes one parameter pattern - datatype - param name
    {
        this.breed = breed;
    }
}

Instantiating a class object

Dog corgi = new Dog("Corgi"); <-- instantiates a Dog object which is an instance of class 
                              Dog passes in String breed value into the constructor to set 
                              the field internal to the class

Invoking class methods

System.out.println(corgi.getBreed());

corgi.setBreed("Great Dane");