int foo = 5;                      // Integer
float bar = 40.25;                // Float
boolean myBool = true;            // Boolean
String message = "Hello World!";  // String

char grade;   // Declaration
grade = 'B';  // Initialization

/* Other data types: byte, double, long */

// Comment on a single line
/*
   Block comments
   Everything in here will be
   treated as a comment
*/

int foo = 100;
foo++;

int bar = 10;
foo = foo - bar;

/*
     + : Addition             - : Subtraction
     * : Multiplication       / : Division
     % : Modulus Division

     ++ : Increase by 1       -- : Decrease by 1
*/

foo += 5;   // Addition assignment operator
foo -= 8;   // Subtraction assignment operator

if (age == 10) {
   message = "one decade old";
}

if (age > 21)
{
   message = "over 21";
}
else if (age < 21)
{
   message = "under 21";
}
else
{
   message = "exactly 21";
}

/*
   == : Equal to                   != : Not Equal to
   >  : Greater than               <  : Less than
   >= : Greater than or equal to   <= : Less than or equal to
*/

int num = 0;

// While Loop
while (num < 100) {
   num++;
}

int sum = 0;

// For Loop
for (int i = 0; i < 50; i++) {
   sum += i;   // adds all values from 0 to 49
}

// Creates an empty "scores" array that can store 20 integers
int[] scores = new int[20];

scores[0] = 92;
scores[1] = 87;
System.out.println( scores[0] );   // Prints 92

// Insert values at instantiation
// Size of array automatically matches number of items
string[] friends = { "Chris", "Jill", "Alex" };

public class Person {
   public string name;
   public int age;
   private int ssn;   // can't be accessed from outside instance

   float wage;        // fields are private by default
}

Person man = new Person();
man.name = "John";
man.age = 30;