title: $ by itself as a variable
body: <p>I was following a tutorial for datamining from <a href="http://www.smashingmagazine.com/2015/04/web-scraping-with-nodejs/" rel="nofollow">here</a>.</p>
  
  <p>I noticed that the variable <strong>$</strong> was declared. What was the reason for a variable name like this?</p>
  
  <pre><code>var request = require("request"),
      cheerio = require("cheerio"),
      url = "http://www.wunderground.com/cgi-bin/findweather/getForecast?&amp;query=" + 02888;
  
  request(url, function (error, response, body) {
      if (!error) {
          var $ = cheerio.load(body),
              temperature = $("[data-variable='temperature'] .wx-value").html();
  
          console.log("It’s " + temperature + " degrees Fahrenheit.");
      } else {
          console.log("We’ve encountered an error: " + error);
      }
  });
  </code></pre>