WMLScript String
Standard Library
WMLScript's
String standard library provides 16 functions to help WAP developers
to perform many kinds of string operations. Some of the functions are
also used to simulate arrays in WMLScript.
In
the following sections, we will look at some of the more commonly
used functions in the String standard library. Then we will see how to simulate
arrays.
Getting the
Character at a Certain Index in a String: charAt() Function
The
charAt() function of the
String standard library can help you get the character at a certain
index in a string. Like in many other programming languages, you can
consider a string as an array of characters in WMLScript. The
character index counts from 0. For example, the first character has
the index 0, the second character has the index 1, etc. The syntax of
charAt() is:
String.charAt(string,
character_index);
The
charAt() function
returns the character at the position character_index of
string. If character_index
is not a valid value, charAt()
returns an empty string. If other errors occur, it returns an
invalid value.
Here
are some WMLScript examples:
var
char = String.charAt("WMLScript Tutorial", 0);
After
executing the above line of script, char
contains the string value W.
var
char = String.charAt("WMLScript Tutorial", -1);
After
executing the above line of script, char
contains an empty string since the second argument is not a valid
character index.
var
char = String.charAt("WMLScript Tutorial", "wml");
After
executing the above line of script, char
contains invalid.
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