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In this case the string is a match only if it contains
alphanumeric characters (or the underscore symbol) and no other characters. The second example
fails because there is a whitespace at the end.
class Main
{
public static function main()
{
var re = ~/^\w+$/;
trace(re.match(???John??™)); // true
trace(re.match(???John ???)); // false
}
}
Quantifiers
Characters, character classes, character sets, or groups can be repeated in a pattern using the quantifiers.
This avoids error - prone repetitions, pattern bloating, and of course gives the opportunity to set optional
repetitions or limit the repetitions to a range of values. The quantifiers described in Table 8 - 9 always
follow a pattern expression that can be a single character or a more complex group.
Table 8-9
Syntax Description
? The expression is optional.
* The expression can be repeated without limits or be absent.
+ The expression must be present and can be repeated several times.
{n} Where n is a positive integer value. The expression must exist exactly n times.


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