Live coded java examples

Car.java

public class Car {

  public int miles = 0;

  public int miles() {
    return 12;
  }

  public static void main(String[] args){
    Car car = new Car();
    // miles variable
    System.out.println(car.miles); // prints 0
    // miles() method
    System.out.println(car.miles()); // prints 12
  }
}

JStoJava.java

public class JStoJava {
  public static void main(String[] args) {
    String[] names = { "Alice", "Bob", "Cory" };
    String result = "";
    for (int i = 0; i < names.length; i++) {
      result += names[i];
    }
    System.out.println(result);
  }
}

Person.java

public class Person {
  public String first;
  public String last;

  public Person(String first, String last) {
    this.first = first;
    this.last = last;
  }

  public String fullName() {
    return first + " " + last;
  }
}

Program.java

public class Program {
  public static void main(String[] args) {
    sayHello();
    System.out.println(add(2, 2));
    Person cj = new Person("CJ", "R");
    System.out.println(cj.fullName());

    Rectangle myRectangle = new Rectangle(100,100);
    Rectangle yourRectangle = new Rectangle(500,50);

    Rectangle.incrementTotal(10);
    Rectangle.incrementTotal(10);

    myRectangle.incrementTotal(10);
    yourRectangle.incrementTotal(10);

    System.out.println(myRectangle.area());
    System.out.println(yourRectangle.area());

    Rectangle.incrementTotal(10);
    Rectangle.incrementTotal(10);

    Rectangle.printTotal();
  }

  // function add(x, y) {
  //   return x + y;
  //   var name = 'CJ';
  //   var name = "CJ";
  // };

  public static int add(int x, int y) {
    int sum = x + y;
    return sum;
  }

  public static void sayHello() {
    char a = 'a';
    System.out.println("Hello World!");
  }

  // public static String add(int x, int y) {
  //   return "x plus y is " + (x + y);
  // }
}

rect.js

function Rect(width, length){
  this.width = width;
  this.length = length;
}

Rect.prototype.area = function(){
  return this.width * this.length;
}

var myRect = new Rect(100,100);

console.log(myRect.area());

Rectangle.java

public class Rectangle {
  public int width;
  public int length;
  public static int theTotal;

  public Rectangle(int width, int length) {
    this.width = width;
    this.length = length;
  }

  public int area() {
    return width * length;
  }

  public static void incrementTotal(int increment) {
    theTotal += increment;
  }

  public static void printTotal() {
    System.out.println(theTotal);
  }

  public static int sumAreas(Rectangle[] rectangles) {

  }
}

Strings.java

public class Strings {
  public static void main(String[] args) {
    // creates an array that will only take Strings, and will only take 4 items
    String[] names = new String[4];
    // even though we haven't put anything in the array, it has a length of 4
    System.out.println(names.length); // 4

    // put string "Hello" in the 0th index;
    names[0] = "Hello";
    // put string "Wrold" in the 1st index;
    names[1] = "World";

    // length is still 4, even though we put 2 items in it.
    System.out.println(names.length); // 4
    // prints the memory address
    System.out.println(names); // [Ljava.lang.String;@7852e922

    doTheThing();
  }

  public static void doTheThing() {
    String[] names = { "Su", "Will", };
    System.out.println(names[0]);

    String[][] fullNames = {
      {"First", "Su"},
      {"Last", "Sylvester"},
    };

    System.out.println(fullNames[0][0]);
  }
}