This is the regular expression I use to be sure if an arbitrary mark-up is an actual valid iframe
code or not:
let someMarkupCode = '...'
let re = /<iframe [.\s\S]*<\/\s*?iframe>/gim
let check = someMarkupCode.match(re)
if (check && check.length > 0) {
console.log('is an IFRAME')
} else {
console.log('is not!')
}
That’s it!
Spotted a typo or (likely) a grammar error? Send a pull request.