如何检查textarea是否为HTML？ [重复]

Question

This question already has an answer here:

• How to check if string contents have any HTML in it? 6 answers

How do I check if what was written in the textarea by the user is valid HTML? It could be with either PHP or Javascript.

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Answer 1

In php, it would be quite simple:

if($text!=htmlspecialchars($text))
{
    echo 'This contains HTML tags!!';
}

Of course, this means an ampersand would be valid, so you could also do something like

function hasHtml($string) {
    if ( $string != strip_tags($string) )
        return true;
}

You can use John Resig's html parser for the Javascript solution, or do something like this:

function is_html(string)
{
  return string.match("/<[^<]+>/").length != 0;
}