1  var escapeHtmlChar = require('./_escapeHtmlChar'),
 2      toString = require('./toString');
 3  
 4  /** Used to match HTML entities and HTML characters. */
 5  var reUnescapedHtml = /[&<>"']/g,
 6      reHasUnescapedHtml = RegExp(reUnescapedHtml.source);
 7  
 8  /**
 9   * Converts the characters "&", "<", ">", '"', and "'" in `string` to their
10   * corresponding HTML entities.
11   *
12   * **Note:** No other characters are escaped. To escape additional
13   * characters use a third-party library like [_he_](https://mths.be/he).
14   *
15   * Though the ">" character is escaped for symmetry, characters like
16   * ">" and "/" don't need escaping in HTML and have no special meaning
17   * unless they're part of a tag or unquoted attribute value. See
18   * [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands)
19   * (under "semi-related fun fact") for more details.
20   *
21   * When working with HTML you should always
22   * [quote attribute values](http://wonko.com/post/html-escaping) to reduce
23   * XSS vectors.
24   *
25   * @static
26   * @since 0.1.0
27   * @memberOf _
28   * @category String
29   * @param {string} [string=''] The string to escape.
30   * @returns {string} Returns the escaped string.
31   * @example
32   *
33   * _.escape('fred, barney, & pebbles');
34   * // => 'fred, barney, &amp; pebbles'
35   */
36  function escape(string) {
37    string = toString(string);
38    return (string && reHasUnescapedHtml.test(string))
39      ? string.replace(reUnescapedHtml, escapeHtmlChar)
40      : string;
41  }
42  
43  module.exports = escape;