description

# RegExp constructor Null safety

RegExp(

1. String source,
2. {bool multiLine: false,
3. bool caseSensitive: true,
4. @Since("2.4") bool unicode: false,
5. @Since("2.4") bool dotAll: false}

)

Constructs a regular expression.

Throws a FormatException if `source` is not valid regular expression syntax.

If `multiLine` is enabled, then `^` and `$` will match the beginning and end of a line, in addition to matching beginning and end of input, respectively.

If `caseSensitive` is disabled, then case is ignored.

If `unicode` is enabled, then the pattern is treated as a Unicode pattern as described by the ECMAScript standard.

If `dotAll` is enabled, then the `.` pattern will match all characters, including line terminators.

Example:

    var wordPattern = RegExp(r"(\w+)");
    var bracketedNumberValue = RegExp("$key: \\[\\d+\\]");

Notice the use of a raw string in the first example, and a regular string in the second. Because of the many character classes used in regular expressions, it is common to use a raw string here, unless string interpolation is required.

## Implementation

    external factory RegExp(String source,
        {bool multiLine = false,
        bool caseSensitive = true,
        @Since("2.4") bool unicode = false,
        @Since("2.4") bool dotAll = false});