User Guide

418 Chapter 6: ActionScript Core Classes
String.substring()
Availability
Flash Player 5.
Usage
my_str.substring(start:Number, [end:Number]) : String
Parameters
start
A number; an integer that indicates the position of the first character of my_str used to
create the substring. Valid values for
start are 0 through String.length - 1. If start is a
negative value, 0 is used.
end A number; an integer that is 1+ the index of the last character in my_str to be extracted.
Valid values for
end are 1 through String.length. The character indexed by the end parameter
is not included in the extracted string. If this parameter is omitted,
String.length is used. If this
parameter is a negative value, 0 is used.
Returns
String: a substring of the specified string.
Description
Method; returns a string comprising the characters between the points specified by the start and
end parameters. If the end parameter is not specified, the end of the substring is the end of the
string. If the value of
start equals the value of end, the method returns an empty string. If the
value of
start is greater than the value of end, the parameters are automatically swapped before
the function executes and the original value is unchanged.
Example
The following example shows how to use substring():
var my_str:String = "Hello world";
var mySubstring:String = my_str.substring(6,11);
trace(mySubstring); // output: world
The following example shows what happens if a negative start parameter is used:
var my_str:String = "Hello world";
var mySubstring:String = my_str.substring(-5,5);
trace(mySubstring); // output: Hello