WMLScript Reference
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This Section outlines
the syntax of the WMLScript language
- Arithmatic
- Logical
-
Bitwise Logical
- Bitwise
Logical
- Assignment
- Comparison
- Miscellaneous
WMLScript Operator Precedence
WMLScript Statement/Functions
- Declarations
- Loops
- Execution Control statements
Pragrams
Comment
Escape
Codes
WMLScript
Operators
A.
Arithmetic Operators
Name
Example
Result
Additional
v1 + v2
Sum of v1 and v2
Concatenation of v1 and v2, if they are strings.
Subtraction
v1 - v2
Different of v1 and v2
Multiplication
v1 * v2
Product of v1 and v2
Division
v1 / v2
Quotient of v2 into v1
Integer Division
v1 div v2
Integer quotient of v2 into v1 (ignoring the remainder)
Modulus
v1 % v2
Integer remainder of dividing v1 by v2
Prifix Increment
++ *v2
(v1+1) *v2
Profix Increment
v1 ++ v2
(v1v2). Is then incremented by 1
Profix Decrement
--v1 v2
(v1 - 1) *v2
Profix Decrement
v1-- *v2
(v1 * v2). V1 is then decremented by 1
B.
Logical Operators
These
operators should return one of the Boolean literals,
true or false. However, this may not happen if
either v1 or v2 is neither a Boolean value nor
a value that easily converts to a Boolean value,
such as 0,1, null, the empty string, or undefined.
Name
Example
Result
Logical AND
v1 && v2
Returns
true if both v1 and v2 are true, false otherwise.
Will not evalute v2 if v1 is false.
Logical OR
v1 v2
Returns
false if both v1 and v2 are false, true otherwise.
Will not evalute v2 if v1 is true.
Logical NOT
!v1
Returns
false if v1 is true otherwise.
C
Bitwise Shift Operators
These
operators work by converting the value in v1 to
a 32 bit binary number and then moving the bits
in the number to the left or the right by the
number of places specified by v2.
Name
Example
Result
Left Shift
v1 && v2
Shifts v1 to the left by v2 places, filling the
new gaps in with zeros
Right Shift
v1 v2
Shifts v1 to the right by v2 places, ignoring
the
bitts shifted off the number
Zero-Fill Right Shift
v1 && v2
Shifts v1 to the right
by v2 place, ignoring
the
bits shifted off the number
and
adding v2 zeros to the left of the number
D.
Bitwise Logical Operators
These
operators work by converting the values in both
v1 and v2 to 32 bit binary numbers and then comparing
the individual bits of these two binary numbers.
The result is returned as a normal decimal number.
Name
Example
Result
Bitwise AND
v1 & v2
ANDs each pair of corresponding bits
Bitwise OR
v1 | v2
Ors each pair of corresponding bits
Bitwise XOR
v1^ v2
XORs (that is, exclusive Ors) each pair of
corresponding bits
Bitwise NOT
-v1
Inverts all the bits in the number
E.
Assignment operators
Name Example
Meaning
Assignment
v1 = v2
Setting v1 to the value of v2
Shorthand Addition
or v1
+= v2
v1 = v1 + v2
Shorthand Concatenation
Shorthand Subtraction
v1 -= v2
v1 = v1 - v2
Shorthand Multiplication
v1 *= v2
v1 = v1 * v2
Shorthand Division
v1 /= v2
v1 = v1 / v2
Shorthand Integer
Division
v1 div= v2
v1 = v1 div v2
Shorthand Modulus
v1
%= v2
v1 = v1 % v2
Shorthand Left
Shift
v1 <<= v2
v1 = v1<< v2
Shorthand Right Shift
v1 = v2
v1 = v1 v2
Shorthand Zero-Fill
Right Shift v1 =
v2
v1 = v1 v2, adding 2 padding zeros
after assignment.
Shorthand AND
v1 &= v2
v1 = v1 & v2
Shorthand XOR
v1 ^= v2
v1 = v1 ^ v2
Shorthand OR
v1 |= v2
v1 = v1 | v2
F.
Comparison operators
These
operators return the Boolean literal values, true
and false. If v1=1 and v2=2, the following statements
are all true.
Name
Example
Meaning
Equal v1=
=1 True
if two operands are strictly equal.
Not Equal v1
!= v2 True
if two operands are strictly not equal.
Greater Than v2
> v1
True if LHS operand is greater than RHS operand.
Greater Than Or Equal v2
> = v2 True
if LHS operand is greater than or equal to RHS
operand.
Less Than v1
< v2 True
if LHS operand is less than RHS operand.
Less Than Or Equal v1
< = v1
True if LHS operand is less than or equal to RHS
operand.
G.
Miscellaneous operators
There
are several other miscellaneous operators in WMLScript.
Name
Example
Meaning
Conditional Operator
evalquery
? v1 : v2 If
evalquery is true, the operatorreturns v1, else
it returns v2.
Comma Operator eval1,
eval2 Evaluates
both eval1 and eval2 while treating the two as
one expression.
Can also be used to declare or set multiple variables
at the same time.
typeof type
of v1 Returns
a number representing the type of v1, which is
not evaluated.
The numbers 0, 1, 2, 3, 4 represent the type integer,
floating point, string,
Boolean and invalid.
Isvalid isvalid
x Returns
a Boolean: true if x is not of type invalid,
and false if x is of type invalid.
H. Operator Precedence
Does 1 + 2 + 3 = 1 + ( 2 * 3) = 7 or does it equal
(1 + 2) * 3 = 9? The table shows precedence with
highest at the top,
and like operators grouped together. The third column
explains whether to read 1+2+3+4 as ((1+2)+3)+4
or 1+((2+(3+(4))).
Operator type
Operators
Evaluations order for like elements
Postfix
[] () expr++ expr--
left to right
Unary
++expr -expr +expr -expr - !
right to left
Type
typeof isvalid
right to left
Multiplicative
* / div %
left to right
Additive
+ -
left to right
Shift
<<
left to right
Relational
< <=
=
left to right
Equality
= = ! =
left to right
Bitwise AND
&
left to right
Bitwise Exclusive
OR
^
left to right
Bitwise Inclusive
OR
|
left to right
Logical AND
&&
left to right
Logical OR
||left to right
right to left
Conditional
? :
right to left
Assignment
= += -= *= /=
div= %= &= ^=
|= right to left
Comma
,
left to right
WMLScript Statements/Functions
The following tables describe WMLScript statements
A. Declarations
Statement
Example
Description
Var
Number = 6 ;
Initializing it to a value is Optional at
the time of
Var N1, N2, N3 = 6;
declaration.
Function extern
function doIt Now ( ) Used
to declare a function with { the specified
parameters.
Statements To return a value the function must
use the return statement. }; extern function
do this (p1,p2,p3)
extern is used so that the function is available
outside of where it is defined.
{ statements } ;
use use
url script2
*http://www.somewhere.com/WMLS
use is used to enable the script scripts/script2.wmls"
; to use pragmas (see table below).
B. Loops
Statement Example Description
For for (var 1=0; i<15; I++) Creates a loop
controlled according to the three optional expressions
enclosed { in the parentheses after the for and
separated by semicolons. The first of x + = i;
these three expressions is the initial-expressions,
the second is the test
do something (x); condition, and the third is
the increment -expression. }
if . . . else if (x < = y) Executes a block
of statements if the condition evaluates to true.
If the {condition evaluates to false, another
Statement
Example
Description
block of statements can be
executed thing + = x; using
else (this is optional).
x + + ;
}
Executes
a block of statements if a test condition
evalutes to true. The loop then { repeats,
testing the condition with each repeat, ceasing
if the condition evaluates
dosomething();
to false. }
{ control to the statement following
the loop.
if (10 = = x)
break;
x++;
}
return x*b;
statements in the
current iteration of a while or for loop; execution
of the loop
{continues with the next
iteration.
if (0 = = (++ count % 2))
continue;
return count*c;
}
returnSthg
(x,y)
{
}
Pragmas
Pragma
Example
Description
url
use url ID "URL"
Used to specify the URL of the WMLScript file
containing the functions we want to use, in URL,
and can then access these functions using the
name specified in ID.
access
use access domain
Used to specify the domain and "domin"
path "path" path from which access
is allowed to function in the current WMLScript.
meta
use meta type property
Used to supply additional information. content
scheme type represents
the type of pragma,property the name of the header
you wish to set, content the value you want to
set the header, and scheme the formatting
of the header
Comment
Comments are notes which the scrip engine ignores,
and which can be used to explain the code.
//this is the syntax for a one line comment_
/* and this is the syntax for a multiple line
comment. The comment can be of any length, as
long as it is contained within the "star slash"
brackets */
Escape
Codes
The following table lists all the literal string
escape codes.
Escape Code
Represents
\'
Single quote
\"
Double quote
\\
Backslash
\ /
Frontslash
\b
Backspace
\f
Newline
\r
Carriage return
\t
Horizontal tab
\xhh
Character hh from the Latin -1 character set (ISO
8859-1) hexadecimal format as two
digits
\ooo
Character ooo form the Latin-1 character set (ISO
8859-1) format as three digits
\uhhhh
Character hhhh from the Unicode character set,
(ISO 8859-1) format as four digits
Standard WMLScript Library Functions
Dialogs
This
library contains functions used to produce simple
use interface cards.
Alert
Usage:
alert(message)
Parameters: message-of
type string, the warning to be displayed to the
user
Comments:
This function displays the message passed
to it as a warning and when the user confirms
they have read the message returns them to the
previous card
Example: Dialogs.alert
("There has been an error");
Confirm
Usage:
confirm(message, ok, cancel)
Parameters:
message-of type string, the positive option
to offer the user
Cancel-of
type string, the negative option to offer the
user
Comments:
a Boolean, true if the user chooses ok, false
if they choose cancel Confirmation, is required.
Example:
bleResult = Dealogs.confirm("Are you sure
you wish to do this "Yes", "Not really");
Prompt
Usage:
prompt(message, default)
Parameters: message-of
type string, the text to display prompting the
user for input default-of type string, the default
text to fill to input box with
Comments: This
function just presents the user with an input
box to fill.
Example:
strResult = Dialogs.prompt ("Enter your
name", "Bob");
Float
This
library contains functions for the manipulation
and conversion of floating point
numbers.
Ceil
Usage:
ceil(value)
Parameters: value
- a floating point number
Returns:
An integer, which is nearest in size to the
value, but not smaller than it.
Comments:
Be careful when using negative numbers, ceil(2.7)=and
NOT-3
Example:
x = Float.ceil (4.1);
// x is assigned the value 5
floor
Usage:
floor(value)
Parameters:
value- a floating point number
Returns:
An integer, which is nearest in
size to the value, but not greater than it
Comments: Be
careful when using negative numbers, floor(-4.1)=
-5 and NOT -4
Example:
x = Float.floor (1.9) ;
Int
Usage:
int(value)
Parameters: value-a floating
point number
Returns:
The integer part of the floating point value
Comments: This simply
returns the integer part of the
value;
it doesn't round the number
Example:
x = float.int(2.9) ;
// x is assigned the value 2
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