User Guide

String class 793
String class
Availability
Flash Player 5 (became a native object in Flash Player 6, which improved
performance significantly).
Description
The String class is a wrapper for the string primitive data type, and provides methods and
properties that let you manipulate primitive string value types. You can convert the value of any
object into a string using the
String() function.
All the methods of the String class, except for
concat(), fromCharCode(), slice(), and
substr(), are generic, which means the methods call toString() before performing their
operations, and you can use these methods with other non-String objects.
Because all string indexes are zero-based, the index of the last character for any string
x is
x.length - 1.
You can call any of the methods of the String class using the constructor method
new String or
using a string literal value. If you specify a string literal, the ActionScript interpreter automatically
converts it to a temporary String object, calls the method, and then discards the temporary String
object. You can also use the
String.length property with a string literal.
Do not confuse a string literal with a String object. In the following example, the first line of code
creates the string literal
first_string, and the second line of code creates the String object
second_string:
var first_string:String = "foo"
var second_string:String = new String("foo")
Use string literals unless you specifically need to use a String object.
Method summary for the String class
Method Description
String.charAt()
Returns the character at a specific location in a string.
String.charCodeAt()
Returns the value of the character at the specified index as a 16-bit
integer between 0 and 65535.
String.concat()
Combines the text of two strings and returns a new string.
String.fromCharCode()
Returns a string comprising the characters specified in the parameters.
String.indexOf()
Returns the position of the first occurrence of a specified substring.
String.lastIndexOf()
Returns the position of the last occurrence of a specified substring.
String.slice()
Extracts a section of a string and returns a new string.
String.split()
Splits a String object into an array of strings by separating the string
into substrings.
String.substr()
Returns a specified number of characters in a string, beginning at a
specified location.
CHAPTER 2
ActionScript Language Reference