title: Uncaught TypeError: Object [object DOMWindow] has no method 'replace'
body: <p>I'm studying javascript. I just want to understand why the strip2() function in the below code doesn't work, and returns an error.</p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
  function strip1(str) {
    return str.replace(/^\s+|\s+$/g, "")
  };
  function strip2() {
    return this.replace(/^\s+|\s+$/g, "")
  };
  
  var text = ' Hello  ';
  console.log(strip1(text));  // Hello
  console.log(strip2(text));  // Uncaught TypeError: Object [object DOMWindow] has no method 'replace'
  &lt;/script&gt;
  </code></pre>
  
  <p>Thanks.</p>