title: JS string formatting operation - substitute a variable value to string
body: <p>In python &amp; other programming languages there's a way to substitute a variable's value in between  a string easily, like this,</p>
  
  <pre><code>name="python"
  a="My name is %s"%name
  print a
  &gt;&gt;&gt;My name is python
  </code></pre>
  
  <p>How do I achieve this in java-script? The plain old string concatenation is very complex for a large string.</p>