# init(newRegularExpressionFromPattern:flags:in:) Creates a JavaScript regular expression value from the specified pattern. ``` init!(newRegularExpressionFromPattern pattern: String!, flags: String!, in context: JSContext!) ``` ## Parameters `pattern` A string to be interpreted as a regular expression pattern. `flags` A combination of zero or more single-letter flags specifying search options. `context` The JavaScript context in which to create the value. ## Return Value A new JavaScript regular expression object. ## Discussion Calling this method creates a JavaScript `RegExp` object, and is equivalent to declaring a regular expression literal (such as `/ab+c/i`) or calling the `RegExp` constructor (for example, `new RegExp("ab+c", "i")`) in JavaScript. The `flags` parameter can include any of the following options: - `g` (global match): match all occurrences of the pattern in a string, not just the first. - `i` (ignore case): perform case-insensitive search. - `m` (multiline): treat the `^` and `$` regular expression tokens as matching the start or end of any line in a string (as delimited by newline or return characters), not just the start or end of the entire string. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)