function escape(string) {
      string = toString(string);
      return (string && reHasUnescapedHtml.test(string))
        ? string.replace(reUnescapedHtml, escapeHtmlChar)
        : string;
    }
Converts the characters "&", "<", ">", '"', and "'" in `string` to their
corresponding HTML entities.

**Note:** No other characters are escaped. To escape additional
characters use a third-party library like [_he_](https://mths.be/he).

Though the ">" character is escaped for symmetry, characters like
">" and "/" don't need escaping in HTML and have no special meaning
unless they're part of a tag or unquoted attribute value. See
[Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands)
(under "semi-related fun fact") for more details.

When working with HTML you should always
[quote attribute values](http://wonko.com/post/html-escaping) to reduce
XSS vectors.

@static
@since 0.1.0
@memberOf _
@category String
@param {string} [string=''] The string to escape.
@returns {string} Returns the escaped string.
@example

_.escape('fred, barney, & pebbles');
// => 'fred, barney, &amp; pebbles'