Regex in javascript check string

Question

I want to check if the string contains html:

const containsHTML = (str) => /<[a-z][\s\S]*>/i.test(str);
console.log(containsHTML('<br>s')) // expect false

In my case i expect false, because s is not wrapped with HTML tag. How to fix the code?

Well your reg exp matches the br tag and says it is fine. Nothing stating the whole line needs to match. — epascarello, Nov 01 '21 at 17:42
obligatory link to https://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/1732454 — epascarello, Nov 01 '21 at 17:42
HTML supports plain text nodes... Don't see why you consider `s` is not allowed after `
`? — trincot, Nov 01 '21 at 17:42
@epascarello, so how to avoid situations if the string is not wrapped in html, could you help please? In the above situation i need to get false — Asking, Nov 01 '21 at 17:46
Depends what it's for. If you're looking to make sure the person didn't add html before doing something like `myContainer.innerHTML = stringFromUser` then most browsers will add missing end tags anyway, so just an opening tag is enough to "get html". — James, Nov 01 '21 at 17:50

score 1 · Answer 1 · edited Nov 01 '21 at 18:00

1

You could try this: /<([a-z]+.*)>.*<\/\1>/i

const containsHTML = (str) => /<([a-z]+.*)>.*<\/\1>/i.test(str)

console.log(containsHTML('<br>s'))    // expect false
console.log(containsHTML('<p>s</p>')) // expect true

edited Nov 01 '21 at 18:00

Mr. Polywhirl

42,981
12
84
132

answered Nov 01 '21 at 17:48

Errorbot1122 THE SECOND

68
10

1

if i set `console.log(containsHTML('
')) // expect true`, but i get false. Why? – Asking Nov 01 '21 at 17:55
I fixed your expression, by reusing the open tag group in the expected closing tag. – Mr. Polywhirl Nov 01 '21 at 18:01
1

@Asking because the regex above only checks for surrounding open-close tags. – Mr. Polywhirl Nov 01 '21 at 18:02

Regex in javascript check string

1 Answers1