How to add a space limit to the character limit code?

Question

Regular Expressions

I am using AJAX. I add a restriction to the field so that Russian characters can be used. What to add so that the space cannot be used, please tell me.

var res = /[^а-яА-ЯїЇєЄіІёЁ ]/g.exec(that.value);
                                            that.value = that.value.replace(res, '');

Answer 1

so remove the space from the regular expression (the last character before the bracket).
[^а-яА-ЯїЇєЄіІёЁ]