Try this, noting that the grammar of HTML is too complex for regular expressions to be correct 100% of the time:
var regex = /(<([^>]+)>)/ig
, body = "<p>test</p>"
, result = body.replace(regex, "");
console.log(result);
If you’re willing to use a library such as jQuery, you could simply do this:
console.log($('<p>test</p>').text());