/hell\u{6F}/u.test('hello'); // -> true /hell\u{6F}/.test('hello'); // -> false

Explain the specifics of the /u flag in regular expressions.

    1 answer 1

    Everything is just like an ax:

    With this flag, the regular form understands expressions like \u{6f} inside the regular schedule, as a Unicode character, without it - understands as a string of consecutive characters u, {, 6, f,}

    The main specifics are the same here: this is a feature appeared in the ecmascript-6 standard, that is, without any compilation in ecmascript-5, the code will not be understood by all browsers.

    There is another small nuance:
    Let x be not an escape symbol, then it is a syntactically valid regular schedule:

     var c = /\x/

    And this is not:

     var c = /\x/u