and end tags set off a section of a

…

<--- title, meta-tags, etc. (not displayed)

<--- main content (displayed)

MS" size="4">
Hello World!


I am 21.

7. Green


8. Yellow




• John


• Mike

Attributes:
Align, text, bgcolor, etc.

an editor!
Forms: later

in “raw” HTML
You may need to tweak HTML files

web-browser engine, for example
What data structure would best represent

documents (and XML documents)
A standard (ok, standards)
Independent of browser,

embedded in HTML documents
The browser’s display engine must distinguish

Netscape renderings are slightly different
Standardized by European Computer Manufacturers

...script goes here

precedence
Overloaded operators
Reserved words

is not an integer operator
5 / 2 yields 2.5
5.1

rules for variables
Strings are very common data types
Rich set

loops

while loops
do-while loops
if-else
variable values in tags
math library
switch
break
labeled break
continue
Booleans

methods

manipulation
Swapping, rollovers, slide shows, etc.
Date, time stuff (e.g. clocks,

the client side
Use of a collection of technologies together

To JavaScript, Steven Estrella, Addison-Wesley
JavaScript for the World Wide

hiding -->
“language=“ for pre IE5 and NS6
Comment for very

load a .js file in header:

to JavaScript -->

Welcome to JavaScript

document.writeln(

Using document.write

document.write ( "Welcome

window.alert

window.alert( "Welcome to\nJavaScript\nProgramming!" );



Click Refresh (or Reload)

entered by user
secondNumber, // second string entered by

The sum is " + sum + "

"" );
for (

= 0,
frequency3 = 0, frequency4 = 0,
frequency5 = 0,

Слайд 40 Rules of Craps
First roll:
7 or 11 is a

win
2, 3, or 12 is a lose
otherwise, roll becomes

your point
Subsequent rolls:
rolling your point is a win
7 or 11 is a lose
otherwise continue to roll

---

Слайд 41 Craps

// variables used to test the state

of the game
var WON = 0, LOST =

1, CONTINUE_ROLLING = 2;
// other variables used in program
var firstRoll = true, // true if first roll
sumOfDice = 0, // sum of the dice
myPoint = 0, // point if no win/loss on first roll
gameStatus = CONTINUE_ROLLING; // game not over yet

---

Слайд 42 Craps
// process one roll of the dice
function play()

{
if ( firstRoll ) {

// first roll of the dice
sumOfDice = rollDice();
switch ( sumOfDice ) {
case 7: case 11:
// win on first roll
gameStatus = WON;
document.craps.point.value = ""; // clear point field
break;
case 2: case 3: case 12:
// lose on first roll
gameStatus = LOST;
document.craps.point.value = ""; // clear point field
break;

---

Слайд 43 Craps
default:
// remember

point
gameStatus = CONTINUE_ROLLING;

myPoint = sumOfDice;
document.craps.point.value = myPoint;
firstRoll = false;
}
}
else {
sumOfDice = rollDice();
if ( sumOfDice == myPoint ) gameStatus = WON;
else if ( sumOfDice == 7 ) gameStatus = LOST;
}

---

Слайд 44 Craps
if ( gameStatus == CONTINUE_ROLLING ) window.alert ("Roll

again");
else {
if ( gameStatus

== WON ) {
window.alert ("Player wins. " + "Click Roll Dice to play again.");
document.craps.point.value = " ";
}
else {
window.alert ("Player loses. " + "Click Roll Dice to play again.");
document.craps.point.value = " ";
}
firstRoll = true;
}
}

---

Слайд 45 Craps
// roll the dice
function rollDice() {
var

die1, die2, workSum;
die1 = Math.floor( 1 +

Math.random() * 6 );
die2 = Math.floor( 1 + Math.random() * 6 );
workSum = die1 + die2;
document.craps.firstDie.value = die1;
document.craps.secondDie.value = die2;
document.craps.sum.value = workSum;
return workSum;
}

---

Слайд 46 Poker Hand

function rand1toN(N) {
return Math.floor(

1+Math.random()*N );
}
function dealcard(card) {
var rank

= new Array(0,"A","2","3","4","5","6","7",
"8","9","T","J","Q","K");
var suit = new Array(0, "Spades", "Hearts", "Diamonds", "Clubs");
card[0] = rank[rand1toN(13)];
card[1] = suit[rand1toN(4)];
}

---

Слайд 47 Poker Hand
var card = new Array(2);
var player =

new Array(10);
var dealer = new Array(10);
for (var i=0; i

i++) {
dealcard(card);
player[i*2] = card[0];
player[i*2+1] = card[1];
dealcard(card);
dealer[i*2] = card[0];
dealer[i*2+1] = card[1];
}

---

Слайд 48 Poker Hand
document.writeln(" PLAYER ");
document.writeln("");
for (var i=0;

i

+ "

"AbCdEfG";
document.writeln( " Character at index 0 in '"+

'" + String.fromCharCode( 87, 79, 82, 68 ) +
"' contains character codes 87, 79, 82 and 68

'" + s2 + "' in lowercase is '" +
s2.toLowerCase() + "'" );
document.writeln( "
'" + s2 + "' in uppercase is '" +
s2.toUpperCase() + "'

new Date();
document.writeln(current);
document.writeln( "String representations and valueOf" );
document.writeln( "toString: "

Get methods for local time zone

Date" );

Set methods for local time zone

is clicked before taking action

function) when an event occurs

- call when this button is clicked
onreset - call

format the time string

device

the event generator