// DrJava saved history v2

8 + 4 * 2 / 1.6

'a'

'a' + 0

'!'

// 'a' is a character literal (character value)

// 8 is an integer literal

// 56.32 is a double literal

char myVariable; // this is a variable declaration

// <type> <name>;

myVariable = 'r'; // this is a variable assignment

// <name> = <expression>;

myVariable

myVariable = 's';

myVariable

// = is assignment operator

// the value on the right-hand side is assigned to the

// variable on the left-hand side

myVariable = 'a';

myVariable + 0

double a;

a

a = 45.32;

a

(int) 'a'

// Typecast: convert a value from one type to its equivalent

// value in another type

(double) 78

(int) 45.6

// the conversion from double to int truncates the decimal

// part of the number

(int) true

int myInt;

int myInt;

// Cannot have multiple variables with the same name.

double myInt;

myInt = 98;

(char) myInt

(double) myInt

int test; char test1; double test2; test = 4;

int test char test1 double test2 test = 4

// Write an initializing declaration for an int variable

// hello with the value 27.

int hello = 27;

// Alternatively, we could do the declaration and initialization

// separately:

// int hello;

// hello = 27;

// == is the comparison operator

23 == 78

12 + 5.3

23 == 78.0

23 == 23.0

23 == 23.4

23 == 23.4 + 1

!(24 == 45)

24 != 45  // this is simpler to write

// Operator precedence:

// Unary + - !

// Binary * / + -

// Equality == !=  < <=, etc

// Logical and: &&

// Logical or: ||

2 + -6


// Primitive types: int, double, float, char, boolean,

//                  short, byte, long


// Non-primitive types are also called class types.

// Example: String

String = "hello";

String myString = "hello";

myString

myString = "hi";

myString.length()

myString = "hi again";

myString.length()

// length() is a method in the String class.

myString = hi again;

myString = "hi again";

String name="Have you read the course info sheet?"
name.substr(1,2)
name.indexOf("ead")
name.indexOf("dedsafdsalkfjar")
name.indexOf("Ha")
' '+0
name.indexOf("H")
name.indexOf("H",2)
name.rindexOf("h",2)
name.length()

import javax.swing.JFrame;

JFrame j;

j = new JFrame(); // create a new JFrame window

j.setVisible(true); // make the window appear on screen

JFrame j1 = new JFrame(); // create a new JFrame window

j1.setVisible(true); // make the window appear on screen

j.setSize(100,200)
j.setVisible(true)
j.setSize(300,400)
j.setVisible(false)
j.setVisible(true)
j.setLocation(100,100)
j.setLocation(50,10)