What different in the two Regular Express?

Question

I have a string, like this:

let str = `... <!-- My -- comment
 test --> ..  <!----> ..
`;

And I want to get the comment part of the HTML string.

I try to use the Regular Express do this.

let reg = /<!(.|\s)*?>/g

str.match(reg) // ["<!-- My -- comment↵ test -->", "<!---->"]

This is ok. But When I try to another Regular Express.

let reg = /<![.|\s]*>/g;
str.match(reg) // null

So what's different in two Regular Express. Why the second is fail?

The Brackets "[" and "]" will match a single character present in the set — Retic, Aug 28 '20 at 07:29
But I add "*" character behind of “]”, It mean zero or many character. — user8930932, Aug 28 '20 at 07:33

score 1 · Accepted Answer · answered Aug 28 '20 at 07:37

1

[.|\s] will match the literal characters ., |, or any space character.
When you use (.|\s) then . will match any character but spaces, and | is the logical or operation.

answered Aug 28 '20 at 07:37

Olian04

1

@Liam it does answer the question, "What is different in the these two Regular Express?". – Olian04 Aug 28 '20 at 07:43
Thank your answer. "." is different between [] and anywhere. – user8930932 Aug 28 '20 at 07:51

1 Answers1