Page 155 - DCAP512_WAP_AND_WML

Unit 11: Using WML Script

 Semicolons mark the ends of statements. Notes
 Comments are marked with “//”.

Task In a group of four analyze why do WML scripts need to be compiled into byte code
before they can be run on a WAP browser?

11.1.2 What are the WML Script Syntax Rules?

WML Script Functions

 An “executable” file in WML Script is called a function

 A function is
 An ordered set of language statements
 Modeled to perform a task
 Selected with the wmls filename extension
 Stored on the application server

 Executed on the device
 Referenced from WML, not contained in it
 Accessed by URL, like a deck or card

Notes A WMLScript function is a named part of the WMLScript compilation unit that you
can call to perform a specific set of statements and to return a value.
The following section describe how you can declare and use WMLScript functions.

Declaration

You can use the function declaration to declare a WMLScript function name (Identifier) with the
optional parameters (FormalParameterList) and a block statement that is executed when the
function is called. All functions have the following characteristics:
 Function declaration cannot be nested.

 Function names must be unique within one compilation unit.
 All parameters to functions are passed by value.

 Function calls must pass exactly the same number of arguments to the called function as
specified in the function declaration.

 Function parameters behave like local variables that have been initialized before the
function body (block of statement) is executed.
 A function always returns a value. By default, it is an empty string (“ “). However, you can
use a return statement to specify other return values.

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