ACTIONSCRIPT 3 Developer’s Guide en

ACTIONSCRIPT 3.0 DEVELOPER’S GUIDE
Using regular expressions
Flags and properties
Flash Player 9 and later, Adobe AIR 1.0 and later
The following table lists the five flags that you can set for regular expressions. Each flag can be accessed as a property
of the regular expression object.
Flag Property Description
g global Matches more than one match.
i ignoreCase Case-insensitive matching. Applies to the A—Z and a—z characters, but not to extended characters
such as É and é .
m multiline With this flag set, $ and ^ can match the beginning of a line and end of a line, respectively.
s dotall With this flag set, . (dot) can match the newline character (\n).
x extended Allows extended regular expressions. You can type spaces in the regular expression, which are ignored
as part of the pattern. This lets you type regular expression code more legibly.
Note that these properties are read-only. You can set the flags (g, i, m, s, x) when you set a regular expression variable,
as follows:
var re:RegExp = /abc/gimsx;
However, you cannot directly set the named properties. For instance, the following code results in an error:
var re:RegExp = /abc/;
re.global = true; // This generates an error.
By default, unless you specify them in the regular expression declaration, the flags are not set, and the corresponding
properties are also set to false.
Additionally, there are two other properties of a regular expression:
The lastIndex property specifies the index position in the string to use for the next call to the exec() or test()
method of a regular expression.
The source property specifies the string that defines the pattern portion of the regular expression.
The g (global) flag
When the g (global) flag is not included, a regular expression matches no more than one match. For example, with
the g flag not included in the regular expression, the String.match() method returns only one matching substring:
var str:String = "she sells seashells by the seashore.";
var pattern:RegExp = /sh\w*/;
trace(str.match(pattern)) // output: she
When the g flag is set, the Sting.match() method returns multiple matches, as follows:
var str:String = "she sells seashells by the seashore.";
var pattern:RegExp = /sh\w*/g;
// The same pattern, but this time the g flag IS set.
trace(str.match(pattern)); // output: she,shells,shore
The i (ignoreCase) flag
By default, regular expression matches are case-sensitive. When you set the i (ignoreCase) flag, case sensitivity is
ignored. For example, the lowercase s in the regular expression does not match the uppercase letter S, the first
character of the string:
Last updated 6/6/2012
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