javascript - Check if a string is html or not

Question

I have a certain string for which I want to check if it is a html or not. I am using regex for the same but not getting the proper result.

I validated my regex and it works fine here.

var htmlRegex = new RegExp("<([A-Za-z][A-Za-z0-9]*)[^>]*>(.*?)</1>");
return htmlRegex.test(testString);

Here's the fiddle but the regex isn't running in there. http://jsfiddle.net/wFWtc/

On my machine, the code runs fine but I get a false instead of true as the result. What am missing here?

Answer 1

A better regex to use to check if a string is HTML is:

/^/

For example:

/^/.test('') // true
/^/.test('foo bar baz') //true
/^/.test('<p>fizz buzz</p>') //true

In fact, it's so good, that it'll return true for every string passed to it, which is because every string is HTML. Seriously, even if it's poorly formatted or invalid, it's still HTML.

If what you're looking for is the presence of HTML elements, rather than simply any text content, you could use something along the lines of:

/</?[a-z][sS]*>/i.test()

It won't help you parse the HTML in any way, but it will certainly flag the string as containing HTML elements.