title: Using throw in a Javascript expression
body: <p>Here is what I want to do:</p>
  
  <pre><code>var setting = process.env.SETTING || throw new Error("please set the SETTING environmental variable");
                                       ^^^^^
  </code></pre>
  
  <p>But the interpreter complains about "Syntax Error: Unexpected token throw".</p>
  
  <p>Is there any way to throw an exception in the same line that we compare whether a value is falsey or not?</p>