Appendix C

JavaScript Commands and Grammar

• JavaScript Statements
• Operator Precedence
• JavaScript Objects
• Reserved Words
• Color Values

Finding information on programming in JavaScript can be a bit like looking for the Holy Grail. Between Netscape's site, online tutorials, and examples, information seems to be everywhere but at your fingertips. So here is the information you're looking for in one place, including statements, operators, and color values.

JavaScript Statements

The statements used to control program flow in JavaScript are similar to Java and C. A statement can span several lines if needed, or several statements can be placed on the same line. The key to remember is that a semicolon must be placed between all statements. Since JavaScript is not strict in its formatting, you must provide the line breaks and indentation to make sure the code is readable and easy to understand later.

break  Terminates the current for or while loop and passes control to the first statement after the loop.

comment  Notes from the script author that are ignored by the interpreter. Single line comments are preceded by //. Multiple line comments begin with /* and end with */.

continue  Passes control to the condition in a while loop and to the update expression in a for loop.

for  Creates a loop with three optional expressions enclosed in parentheses and separated by semicolons, followed by a set of statements to be executed during the loop:

for( initialExpression; condition; updateExpression) {
statements...
}

The initial expression is used to initialize the counter variable, which can be a new variable declared with var. The condition expression is evaluated on each pass through the loop. If the condition is true, the loop statements are executed. The update expression is used to increment the counter variable.

for…in  Iterates a variable for all of properties of an object:

for (variable in object) {
statements...
}

For each property, it executes the statement block.

function  Declares a JavaScript function with a name and parameters. To return a value, the function must include a return statement. A function definition cannot be nested within another function.

function name ([parameter] [...,parameter]) {
statements...
}

if…else  A conditional statement that executes the first set of statements if the condition is true, and the statements following else if false. If...else statements can be nested to any level.

if (condition) {
statements...
} [else {
statements...
}]

return  Specifies a value to be returned by a function.

return expression;

var  Declares a variable and optionally initializes it to a value. The scope of a variable is the current function or, when declared outside a function, the current document.

var variableName [=value] [..., variableName [=value]]

while  Repeats a loop while an expression is true.

while (condition) {
statements...
}

with  Establishes a default object for a set of statements. Any property references without an object are assumed to use the default object.

with (object) {
statements...
}

This statement is especially useful when applied to the Math object for a set of calculations. For example,

with (Math) {
var Value1 = cos(angle);
var Value2 = sin(angle);
}

replaces

{
var Value1 = Math.cos(angle);
var Value2 = Math.sin(angle);
}

Operator Precedence

Precedence refers to the order in which compound operations are computed. Operators on the same level have equal precedence. Calculations are computed from left to right on all binary operations beginning with the operators at the top of the list and working down.

JavaScript Objects

JavaScript is an object-oriented language, and as such, includes a set of built-in objects to represent the HTML document, especially form elements. Built-in objects can be accessed by both the client and server.

String  Contains a string of characters.

Math  Provides numerical constants and mathematical functions.

Date  Stores a date in the number of milliseconds since 1/1/1970, 00:00:00, and returns a date string in the format "Thu, 11 Jan 1996 06:20:00 GMT".

Document  The foundation object created with an HTML <BODY> tag and used to write other information to the page.

Form  An object for gathering and echoing data, created by HTML <FORM> tags.

Window  The highest precedence object accessible by JavaScript relating to the current open Navigator window. New windows and frames can also be created.

Reserved Words

The following words cannot be used as user objects or variables in coding JavaScript. Not all are currently in use by JavaScript-they are reserved for future use.

Abstract	for	public
boolean	function	reture
break	goto	short
byte	if	static
case	implements	super
catch	import	switch
char	in	synchroniz
const	instanceof	thised
continue	int	throw
default	interface	throws
do	long	transient
double	native	true
else	new	try
estends	null	var
false	package	void
final	private	while
finally	protected	with
float

Color Values

Colors can be referenced in a variety of properties in two ways: by using the string literal or a RGB hexadecimal triplet formed by combining the three color values. For example, aliceblue is represented as F0F8FF.

Color/string literal	Red	Green	Blue
aliceblue	F0	F8	FF
antiquewhite	FA	EB	D7
aqua	00	FF	FF
aquamarine	7F	FF	D4
azure	F0	FF	FF
beige	F5	F5	DC
bisque	FF	E4	C4
black	00	00	00
blanchedalmond	FF	EB	CD
blue	00	00	FF
blueviolet	8A	2B	E2
brown	A5	2A	2A
burlywood	DE	B8	87
cadetblue	5F	9E	A0
chartreuse	7F	FF	A0
chocolate	D2	69	1E
coral	FF	7F	50
cornflowerblue	64	95	ED
cornsilk	FF	F8	DC
crimson	DC	14	3C
cyan	00	FF	FF
darkblue	00	00	8B
darkcyan	00	8B	8B
darkgoldenrod	B8	86	0B
darkgray	A9	A9	A9
darkgreen	00	64	00
darkkhaki	BD	B7	6B
darkmagenta	8B	00	8B
darkolivegreen	55	6B	2F
darkorange	FF	8C	00
darkorchid	99	32	CC
darkred	8B	00	00
darksalmon	E9	96	7A
darkseagreen	8F	BC	8F
darkslateblue	48	3D	8B
darkslategray	2F	4F	4F
darkturquoise	00	CE	D1
darkviolet	94	00	D3
deeppink	FF	14	93
deepskyblue	00	BF	FF
dimgray	69	69	69
dodgerblue	1E	90	FF
firebrick	B2	22	22
floralwhite	FF	FA	F0
forestgreen	22	8B	22
fuchsia	FF	00	FF
gainsboro	DC	DC	DC
ghostwhite	F8	F8	FF
gold	FF	D7	00
goldenrod	DA	A5	20
gray	80	80	80
green	00	80	00
greenyellow	AD	FF	2F
honeydew	F0	FF	F0
hotpink	FF	69	B4
indianred	CD	5C	5C
indigo	4B	00	82
ivory	FF	FF	F0
khaki	F0	E6	8C
lavender	E6	E6	FA
lavenderblush	FF	F0	F5
lawngreen	7C	FC	00
lemonchiffon	FF	FA	CD
lightblue	AD	D8	E6
lightcoral	F0	80	80
lightcyan	E0	FF	FF
lightgoldenrodyellow	FA	FA	D2
lightgreen	90	EE	90
lightgrey	D3	D3	D3
lightpink	FF	B6	C1
lightsalmon	FF	A0	7A
lightseagreen	20	B2	AA
lightskyblue	87	CE	FA
lightslategray	77	88	99
lightsteelblue	B0	C4	DE
lightyellow	FF	FF	E0
lime	00	FF	00
limegreen	32	CD	32
linen	FA	F0	E6
magenta	FF	00	FF
maroon	80	00	00
mediumaquamarine	66	CD	AA
mediumblue	00	00	CD
mediumorchid	BA	55	D3
mediumpurple	93	70	DB
mediumseagreen	3C	B3	71
mediumslateblue	7B	68	EE
mediumspringgreen	00	FA	9A
mediumturquoise	48	D1	CC
mediumvioletred	C7	15	85
midnightblue	19	19	70
mintcream	F5	FF	FA
mistyrose	FF	E4	E1
moccasin	FF	E4	B5
navajowhite	FF	DE	AD
navy	00	00	80
oldlace	FD	F5	E6
olive	80	80	00
olivedrab	6B	8E	23
orange	FF	A5	00
orangered	FF	45	00
orchid	DA	70	D6
palgoldenrod	EE	E8	AA
palegreen	98	FB	98
paleturquoise	AF	EE	EE
palevioletred	DB	70	93
papayawhip	FF	EF	D5
peachpuff	FF	DA	B9
peru	CD	85	3F
pink	FF	C0	CB
plum	DD	A0	DD
powderblue	B0	E0	E6
purple	80	00	80
red	FF	00	00
rosybrown	BC	8F	8F
royalblue	41	69	E1
saddlebrown	8B	45	13
salmon	FA	80	72
sandybrown	F4	A4	60
seagreen	2E	8B	57
seashell	FF	F5	EE
sienna	A0	52	2D
silver	C0	C0	C0
skyblue	87	CE	EB
slateblue	6A	5A	CD
slategray	70	80	90
snow	FF	FA	FA
springgreen	00	FF	7F
steelblue	46	82	B4
tan	D2	B4	8C
teal	00	80	80
thistle	D8	BF	D8
tomato	FF	63	47
turquoise	40	E0	D0
violet	EE	82	EE
wheat	F5	DE	B3
white	FF	FF	FF
whitesmoke	F5	F5	F5
yellow	FF	FF	00
yellowgreen	9A	CD	32