matches operator

*

Acts as a wildcard, matching zero or more characters in the string expression

?

Acts as a wildcard, matching a single character in the string expression

[ ]

Any one of the characters between the two brackets is valid as a match for the next character in the string expression. For example, the following component of a regular expression indicates that a, b, or c is valid as a match:

  [abc]

-

Creates a range within the bracket delimiters, such that any character within the range is valid as a match for the next character in the string expression. For example, the following component of a regular expression indicates that a, b, or c is valid as a match:

  [a-c]

The hyphen (-) has no special meaning outside of bracket delimiters.

^

The caret reverses the meaning of the bracket delimiters. Any character other than the delimited characters is valid as a match for the next character in the string expression. For example, the following component of a regular expression indicates that any character other than a, b, or c is valid as a match:

  [^abc]

The caret has no special meaning other than in the first position within brackets.

\

Indicates that the next character is to be compared to a single character in the string expression. The backslash (\) is called an escape character because it causes an escape from the usual processing; the escape character is not compared to any character in the string expression. The escape character usually precedes a character that is otherwise meaningful in the regular expression, such as an asterisk (*) or a question mark (?).

When you use the backslash as an escape character (as is the default behavior), a problem arises because EGL uses the same escape character to allow inclusion of a double quotation mark in any text expression. In the context of a regular expression, you must specify two backslashes because the text available at run time is the text that lacks the initial backslash. To avoid this problem, specify another character as the escape character by using the escape keyword, as shown in "Examples" in this topic. Note that you cannot use a double quotation mark (") as an escape character.

myVar01 = "abcdef";

// evaluates as TRUE 
if (myVar01 matches "a?c*")
   ;
end

myVar01 = "ab*def";

// evaluates as TRUE
if (myVar01 matches "ab\\*[abcd][abcde][^a-e]")
   ;
end

myVar01 = "ab*def";

// the next logical expression evaluates to "true"
if (myVar01 matches "ab+*def" escape "+")
    ;
end