title: Can someone help me with this syntax?
body: <p>This maybe silly but I'm unfamiliar with the syntax here:</p>
  
  <pre><code>var stdin = '';
  process.stdin.on('data', function (chunk) {
    stdin += chunk;
  }).on('end', function() {
    var lines = stdin.split('\n');
    for(var i=0; i&lt;lines.length; i++) {
      process.stdout.write(lines[i]);
    }
  });
  </code></pre>
  
  <p>I'm supposed to write a program that squares a number, which I know how to do, but I've never encountered this type of structure. I understand the loop and that <code>process.stdout.write</code> is essentially <code>console.log</code> The test cases inputs are 5 and 25. Outputs should be 25 and 625.</p>
  
  <p>Where am I supposed to write the code to do this?</p>